Updating PR description fails when a PR reviewer is not a member of the workspace without an error message indicating the issue

Issue Summary

Assume that you have a pull request in a repo with reviewer userA.

If userA leaves the company and their access is revoked completely from the workspace (not just the repo), then the description of this PR cannot be updated, unless userA is removed from the reviewers.

No error message is displayed to the user trying to update the description to indicate what the problem is and what the user needs to do.

Steps to Reproduce

1. Create a pull request in a Bitbucket Cloud repo and add a user (e.g. userA) as a reviewer to this PR
2. Remove userA from the workspace where this repo belongs to
3. Go to the PR created in step 1, and click on the content of the Description field to update its description
4. When clicking Save to update the description, the updated description shows to be saved initially
5. Refresh the page on your browser

Expected Results

An error message should be displayed indicating that the PR description could not be updated because reviewer userA is no longer a member of the workspace, and asking to remove userA from reviewers in order to update the PR description.

Actual Results

The description no longer shows to be updated and there is no error message indicating what the problem is.

In Firefox, the following error shows:

"Something went wrong
We couldn’t update the description. Wait a few minutes and then try again."

Workaround

Users can update the PR description if they remove from reviewers the one who doesn't have access to the workspace.

There is no workaround for the lack of an error message indicating the problem and what the user needs to do in order to update the PR description.