☒are you seeing any JS errors? Could you run the project code from the episode locally and replicate the issue?

 ☒ ooo that could be tricky. You could do an in app or email notification whenever it finishes. On this site, I have a slack notification which lets me know when it's finished. You may look into something like this https://superuser.com/a/1460400/86978 and then implement it with a progress bar ui like in this episode https://www.driftingruby.com/episodes/realtime-client-updates-from-background-jobs-with-stimulus

☒

 ☒  Yes, it would probably be the 24.hours.from_now set for the expiration. Personally, I don't think that the JWT token should be a long living one. If the server returns that the token is expired, the consuming app should have a mechanism to validate a new one without user interaction.

 ☒ Great question. Since the stimulus controller is creating a hidden element, you would need to remove that hidden element with something like this. I would console log the file to see what parameters are available and then remove the hidden element based on those parameters.

dropzone.on("removedfile", file => {
 
});

 ☒ Can you post an example of the parameters that are getting posted to the controller?

Also, do you have 

has_many_attached :evidences

In your event model?