Block sometimes reverts to settings view

[helen]

Describe the bug
I noticed a couple times during testing that after a while of leaving the editor open the block had reverted back to the settings view. I believe both times I had set up credentials within that page load but unfortunately I am not sure, I can test some more later to make more details reproduction steps.

Steps to Reproduce

1. Insert a map block.
2. Set up credentials and see the map view.
3. Leave the editor open for a while.
4. See map block reverted back to credential entering view, with said credentials in the fields.

Expected behavior
I would expect it not to switch back like that :)

Screenshots
I didn't take one because credentials but I can take and edit one if this isn't explanatory enough.

Environment information
This is in Firefox, I see the following in my console although unclear if it's directly related:

Warning: Invalid DOM property `readonly`. Did you mean `readOnly`?

Additional context

[helen]

I've kept an editor open for a while to see if this happens, it did happen again at some point overnight but my wifi was off so I think it was related to that. The error I got there was:

Bootstrap.init(): initialization failed because the server returned error 0 ().

But otherwise if I'm still on wifi I haven't come across this again. If that seems expected, we can close this!