I have called UBS number which is shown in the error message, they also confirm again that their technical stuff is working on that issue and that they are aware of it. Seems like a general issue with Pixel Phones, I not mentioned anything about GrapheneOS. Hopeyfully they push out a patch soon
Did anybody know, how to revert to an older Version of UBS Access after re-install ? How can I re-install any older version, is that possible?