Hello,
Pywikibot apparently logins too frequently with its Pywikibot-test account, see:
[urbanecm@mwlog1001 ~/frequent-logins-T256533/data]$ cat goodpass.log goodpass.log-20200828 goodpass.log-20200827 | bash ../analyze.sh [...] 2833 Pywikibot-test [...] [urbanecm@mwlog1001 ~/frequent-logins-T256533/data]$
That's about 41 logins per hour, and for the analyzed data, it constitutes ~1,5 % of all login requests.
IIRC, Pywikibot should cache the session, from T256533#6408832, Matthias Winkelmann is the only one pywikibot based bot. Perhaps something went bad with login handling recently?