mediawiki uses numerical values for subjects, e.g. "sub": 4.

Since version 2.10 pyjwt enforces subject to be of type string, see jpadilla/pyjwt#1017

This makes jwt.decode failing with Exeption: Subject must be a string

Workaround:
Downgrage pyjwt<2.10

Solution:
set options = {"verify_sub": False} for jwt.decode