Unable to receive ads since three days, sponsored images do not pay - Failed to get signed tokens

Briefly describe your issue:
I’m unable for three days now to receive ads and being paid to see sponsored images.
rewards-internals only show me this error:
AM:ERROR:refill_unblinded_tokens.cc(232)] Failed to get signed tokens

What Operating System and Brave version are you using (Menu --> About Brave)?
Windows 10 20H2 (Build 19042.1348)
Brave Version 1.31.91 Chromium: 95.0.4638.69 (Offizieller Build) (64-Bit)

Is your browser wallet currently verified? (yes/no)
no

What date did you verify your wallet?

Have you been able to successfully receive payments in the past?
yes, it worked from june to the middle of november

Are you using a VPN? (yes/no)
no

Are you in a supported region (see here for list of supported regions)?
yes

Does your device pass the SafteyNet check (Android only)?

Have you manually turned off Auto-contribute on all of your devices linked to Uphold??
no confirmed wallet

Quick addition-Edit: After the first occurance of the problem i had upgraded my windows 10 to 11, but have since reverted to the previous system via backup with the same local files for brave.