LTI 1.3 problem. Submission Type Placement modal doesn't close after successful deep linking

[ChrisVouga]

Context:  I'm developing a LTI 1.3 tool that runs inside of Canvas. The placement is the "Submission Type Placement". I do not have this problem when running canvas locally in docker (canvas.docker). I'm running into this problem on a remote instance of canvas (asu-dev.instructure.com).

Expected Behavior: After successfully deep linking content in the submission type placement, canvas will close the modal.

Actual Behavior: After successfully deep linking the modal remain open indefinitely.

When I close the modal when it says "Retrieving Content" and save the assignment, the expected content is shown when viewing the assignment. The only problem is that modal never closes even though the deep linking is successful. The responses in the network tab look okay.

Is this problem with my LTI provider app or the Canvas instance my app is running inside of.

Any theories or things I should do would help. Thanks.

[matthew_buckett]

We've got a local tool that uses the deep linking flow to return items to Canvas (ltiResourceLink in this case). Could it be that your "aud" value on the returned JWT in the deep linking response is still set for your local Canvas instance instead of "https://canvas.instructure.com"?

If you are using a JWKs URL on your developer key is this accessible to the Canvas instance?

[matthew_buckett]

Ah, you said it successfully sets up the assignment link so I I'd expect it to be signed ok. Sorry I'm stumped at this point, I'm guessing no errors in the console?

[ChrisVouga]

Thanks for the feedback.

Yeah we're pretty stumped too. I've reproduced with problem with a different LTI tool so my current theory is there might be something wrong with the canvas instance I'm running the tools in. I don't have this problem in the local canvas instance I'm running in docker only the instance running at https://asu-dev.instructure.com. I've talk with the admin for the instance and he also agreed there might be something wrong on their side.

If we figure it out I'll try to post my answer in this forum

[ChrisVouga]

UPDATE:

I did not find a solution so I'm using the "assignment selection" placement instead of the "submission type selection" placement.

This ends up satisfying our app's requirements.

I think the problem is a bug in the instance of canvas I'm launching it from

[116086425434479]

I had this issue as well and changing the secure flag on the cookie (along with setting samesite=None) seemed to resolve for me. Obvisouly not a proper solution though but seems to indicate a bug in canvas-lms.

[crvouga]

I was not able to solve this. We ended up using the assignment selection placement with the deep linking request option selected instead of the submission placement. I think this was a bug with the ASU Dev Canvas instance because it would work on a local instance of Canvas but not  on the ASU Dev Canvas instance.