Brave Rewards stuck at 0

Description of the issue:
How can this issue be reproduced?

  1. Upgrade from 1.17.73 to 1.19.88
  2. Downgrade back to 1.17.73 (this problem:

Expected result:
Brave rewards should increase since I see the ads popping up on a regular basis, but no, it’s stuck at 0.
Brave Version( check About Brave):
Additional Information:
OS: NixOS unstable

Is it possible to delete the wallet file and restore it from passphrase so that it could work again?