Causing issue in course builder by doing a bunch of things very quickly

[willmiddleton-lifterlms]

Reproduction Steps

Video of this: https://www.loom.com/share/ea6ca692c2b147d7ac0d87e77501193d

I'm not sure if this one is a known issue -> If you do a bunch of things very quickly in the course builder, you can trigger an error I don't understand. The easiest way to trigger this is to:

• create a quiz
• create a question
• duplicate the question a bunch
• delete a bunch of questions
• just keep duplicating and deleting until the course builder tries to save automatically
• the 'save' button will infinitely spin and none of your future changes will be saved (until you reload the page and start again)

Error Messages / Logs

From the Inspector Console:

<!-- Paste error logs / backtraces below this line -->
 at Sync.js:460
    at Function.dr (underscore.min.js?ver=1.8.3:2)
    at u (Sync.js:448)
    at Sync.js:439
    at Function.dr (underscore.min.js?ver=1.8.3:2)
    at u (Sync.js:438)
    at Sync.js:469
    at Function.dr (underscore.min.js?ver=1.8.3:2)
    at Sync.js:468
    at Function.dr (underscore.min.js?ver=1.8.3:2)
</details>

This issue has be recreated:

• [ ] Locally
• [x] On a staging site
• [x] On a production website
• [x] With only LifterLMS and a default theme

[thomasplevy]

Possibly related to https://github.com/gocodebox/lifterlms/issues/1003 and gocodebox/lifterlms-assignments#47