The following bugs have been reported to Canvas and Canvas has identified them as known issues; we do not have an estimated time for these bugs to be fixed. We will post any updates to this knowledge base article.
Ongoing
Issue: Copyleaks AI Detection & Plagiarism tool returns 400 Bad Request – Request Header Or Cookie Too Large (nginx) after being enabled on multiple Canvas assignments.
Canvas Area: Plagiarism and AI Detection
Status: Copyleaks Bug - Reported to CopyLeaks
Canvas Case #: CASE-00054887
Expected Behavior: Instructors should be able to enable the Copyleaks AI Detection & Plagiarism tool on multiple Canvas assignments without error. The tool should consistently launch and save settings across assignments within the same course.
Observed Behavior: After enabling Copyleaks on approximately 9 assignments within a course, the tool fails to load and returns: 400 Bad Request Request Header Or Cookie Too Large Nginx. Testing indicates that Copyleaks creates a new browser cookie each time the tool is enabled on an assignment. Once multiple cookies accumulate, the HTTP request header exceeds the server limit, triggering the nginx error. The issue was replicated in: Google Chrome and separate Chrome profile. Clearing cookies resolves the issue temporarily, but the error reoccurs once cookies accumulate again.
Impact / Severity: Medium
Date Reported to CopyLeaks: February 26, 2026
Date Last Updated: February 26, 2026
Notes from Canvas Support:
- Feb 26, 2026 – Case opened with CopyLeaks Support
Workaround (if available)
- Clear Copyleaks-related browser cookies (temporary fix).
- Use Chrome Incognito mode to enable the tool (not ideal; requires separate login/session).
Issue: Students are unable to view New Quiz feedback on mobile application
Canvas Area: New Quizzes / Grades / Canvas Student App
Status: Canvas Bug – Fix in Progress
Canvas Case #: CASE-13617354
Expected Behavior Students should be able to reopen completed New Quizzes in the Canvas mobile app and view question-level feedback when feedback is available and released.
Observed Behavior When accessing a course via the Canvas Student mobile app, students are unable to reopen completed New Quizzes to view feedback if the quiz “Until” date has passed. No error message is displayed, and feedback does not appear in the Grades area.
Impact / Severity Medium. Affects students using the Canvas mobile app to review instructor feedback on completed assessments.
Date Reported to Canvas February 12, 2026
Date Last Updated February 19, 2026
Notes from Canvas Support
- Feb 12, 2026 – Case opened with Canvas Support after confirming feedback was properly configured and visible in browser.
- Feb 13, 2026 – Case escalated to Level 2 Support
- Feb 19, 2026 - Canvas L2 Support confirmed a known issue where students cannot access New Quiz submissions in the mobile app if the quiz “Until” date is set in the past. Engineers are actively working on a fix.
Workaround (if available) Temporarily remove the “Until” date or extend it to a future date to allow mobile access. Alternatively, students can view feedback using a web browser at grcc.instructure.com (Safari, Chrome, etc.) or on a desktop/laptop device.
Resolved
Issue: Turnitin Options Appearing Without Integration
Canvas Area: Assignments / Plagiarism Framework
Status: Confirmed Canvas Bug – Fix Pending
Canvas Case #: CASE-13231192
Expected Behavior Instructors should only see plagiarism review options for tools currently integrated into the Canvas instance. References to Turnitin should not appear if the tool is not configured.
Observed Behavior Instructors are seeing options to submit assignments via Turnitin despite the institution using Copyleaks and never having installed a Turnitin integration.
Impact / Severity Medium. Causes instructor confusion and administrative overhead for institutions using alternative plagiarism frameworks.
Date Reported to Canvas November 10, 2025
Date Last Updated February 19, 2026
Notes from Canvas Support
- Nov 10, 2025 – Case opened with Canvas Support.
- Nov 10, 2025 – Canvas confirmed this is a known product defect; engineers are currently investigating a resolution.
- Feb 19, 2026 - A fix has been implemented by Canvas support, this should no longer be seen.
Workaround (if available) Instructors should ignore the Turnitin references and continue to select Copyleaks from the plagiarism review dropdown.
Issue: Discussion Post Dates Not Displaying in SpeedGrader
Canvas Area: SpeedGrader / Discussions
Status: Confirmed Canvas Bug – Fix Released
Canvas Case #: CASE-13570867
Expected Behavior
Instructors should consistently see discussion post and reply timestamps in SpeedGrader for all student submissions.
Observed Behavior
Discussion post and reply dates briefly appear when SpeedGrader loads, then disappear. In some cases, dates do not display at all.
Impact / Severity
Medium. Affects grading accuracy and instructor ability to verify submission timing, leading to increased faculty support requests and administrative overhead.
Date Reported to Canvas: 2/3/2026
Notes from Canvas Support
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Feb 3, 2026 Issue reported to Canvas Support
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Feb 3, 2026 Canvas confirmed that this is a known issue and is being worked on by Canvas Engineers
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Feb 6, 2026 Canvas Engineers have deployed a fix
Workaround: Instructors can click the link to view the full discussion context to verify post timestamps. Additionally, hovering over the “Last Week” text in SpeedGrader will display the exact date and time of the post. While not optimal, this can save time when checking submission timing.
Issue: Quiz Submissions Not Visible in Gradebook and False “Multiple Session” Warnings
Canvas Area: Quizzes / Gradebook / Session Management
Status: Confirmed Canvas Bug – Fix Released
Canvas Case #: CASE-13485141
Expected Behavior Instructors should be able to view all student quiz submissions directly from the Gradebook when a student has completed an attempt. Students should only receive a “multiple session” warning if a quiz is actively open in more than one browser window, tab, or device.
Observed Behavior Instructors cannot see some completed quiz submissions from the Gradebook, even though quiz attempt logs show full student activity and students can view their own results from the module. Students receive a “You have already started this quiz in a different session” warning when using a single device and browser window, and in some cases before opening the quiz for the first time.
Impact / Severity Medium. Causes instructor uncertainty about whether a submission occurred, student anxiety over potential academic integrity flags, and increased administrative workload to manually review moderation logs and Canvas support transcripts.
Date Reported to Canvas January 20, 2026
Date Last Updated February 3, 2026
Notes from Canvas Support
- January 20 - Case opened with Canvas Support
- January 21 - Provided additional information and examples to Canvas Support
- January 22- Canvas confirmed that this is a bug, and is being investigated by Engineering
- February 3- Canvas confirmed that a fix has been applied
Workaround (if available) Instructors should check the quiz log and verify if the attempt exists, if it does a grade may show and instructors can manually enter that into SpeedGrader.
Issue: Letter Grades Persistent in Total Column
Canvas Area: Gradebook
Status: Confirmed Setting Misalignment - Fix Applied
Canvas Case #: CASE-12999132
Expected Behavior When the "Enable course grading scheme" option is unchecked in Course Settings, the Total column in the Gradebook should display only numerical values (percentage or points) and hide letter grades.
Observed Behavior Letter grades continue to display in the Gradebook Total column even after the instructor disables the grading scheme. Engineering investigation suggests the API parameter for the grading scheme may remain stuck in a "true" state at the course level.
Impact / Severity Medium. Impacts grade privacy and clarity; students may see a calculated letter grade that the instructor does not intend to use or has not yet finalized.
Date Reported to Canvas September 25, 2025
Date Last Updated January 8, 2026
Notes from Canvas Support
- Sept 25, 2025 – Case opened; issue escalated to L2 Support.
- Oct 15, 2025 – Issue escalated to Engineering; confirmed that the grading scheme state is failing to update via API.
- Dec 17, 2025 – Engineering investigation ongoing; priority review requested.
- Jan 8, 2026 – Root cause identified as a conflict with Account-level default settings and issue has been resolved.