Alright, I found the origin of the issue: https://en.wikipedia.org/wiki/Privacy_Badger
When the addon is enabled: I got the the warning and can’t access the Security feed tab in Yunohost admin panel
When the addon is disabled: everything works fine.
Solutions
User side : whitelist your own domain in the addon setting
More info:
- Firefox Quantum 59.0.1
- Privacy Badger version 2018.2.5