Unable to sign in with Firefox after a few weeks


I’ve been running into an issue every few weeks, I find I can no longer sign in on firefox. (chrome and other browsers are fine but I don’t want to use those)

I come to sign in and the sign in page logs in as normal but rather than loading the yunohost.org user page it goes back to the sign in page.
this will repeat until i clear the history on Firefox and any cookies for my instance.
then all is fine again.

I can still sign in as Admin without issue, but nothing I do will fix it.

Hosted at a Datacenter with https://prgmr.com/xen/

2.7.10 (stable)
2.7.7 (stable)
2.7.7 (stable)
2.7.7 (stable)

any tips would be fantastic.

May be some firefox plugins or configuration disable some features ?