PU no longer opens in firefox

For a couple of days now firefox will not open my PU. It keeps loading, showing white screen. Refresh and/or forced (=CTRL+F5) refresh do not help.
It is my understanding that a refresh of a firefox instance is needed to update several of the planning tools I have installed.
Is this a known issue? Any help, guys?

Following advice on the discord I disabled the extensions (PMMG extended and FIO client) but to no avail. Following devs advice it works when opening the instance in a private window in firefox. But will I not lose data transfer to my analytics (pruplanner, FIO, etc. etc.)? I thought when I boarded PU that firefox is needed just for the data flow, while playing it doesnt matter in which browser. Was that a misconception?