Extension stopped working on update for several users

Add-ons Development
#1

Some users have reported that my extension stopped working after the latest major update.
I cannot reproduce this error and for most other users there doesn’t seem to be any problem.
This new update is asking for 2 additional permissions. Is it possible that an extension breaks completely if a user doesn’t accept those new permissions? I was expecting that only those parts of the application that are using those permissions would fail.
Apparently the extension starts working again, when the user uninstalls it, restarts Firefox and then re-installs the extension.

Update: Just now one user confirmed that he did accept the new permissions but he still had to uninstall and re-install the extension in order for it to start working again.

#2

Do your extension use indexedDB?
Does users experiencing problems have 1st party isolation enabled (privacy.firstparty.isolate;true) ?

#3

I’m using the Web Storage API.
I know nothing about the user’s configs, I will ask them about this setting.
Thank you

Update: But I doubt it has anything to do with storage. It seems as if no content scripts are being loaded (neither on websites nor priviledged ones like for browserAction or options page). And after the user has re-installed the extension all his stored data is available - so no losses from storage.

Update 2: I think that the only parts that still work are the browserAction, sidebarAction and options page (HTML), but without content scripts.