As you have seen firefox have globally addon disabled.
See: https://support.mozilla.org/en-US/kb/add-ons-disabled-or-fail-to-install-firefox
Add-ons disabled or fail to install on Firefox
Please do not delete your add-ons as an attempt to fix. You will lose any data related to the add-on.
So the question relate to mageia is: Will be arrive the patch from about:studies in the next 6 hour? Is the issue the same in Mageia 6.1 stable and in MGA7b3?
https://blog.mozilla.org/addons/2019/05/04/update-regarding-add-ons-in-firefox/ Updates:
Clarified that the Studies fix applies only to Desktop users of Firefox distributed by Mozilla. Firefox ESR, Firefox for Android, and some versions of Firefox included with Linux distributions will require separate updates. (May 4, 12:03 EST)
Does require Firefox on mageia separate update?
Note that XPI certificate is not the same of your bank site certificate (https).