Can not login in Firefox

I can not login with my Satisfaction account in this forum in Firefox. I have disabled all addons and tracking protection in Firefox but it does not help. I am using chrome based browser Vivaldi now to login but like to use my default Firefox browser for this. What can be the problem?

Maybe try clearing the cookies and site data in Firefox.

I tried everything, cleared cache, cookies, everything. But I can not login using Firefox :slight_smile: