Kmail no connection to gmail after password change

Good evening at all!

Earlier this week I changed my Google password. After changing it in Kmail, there is no 
connection to gmail.
I only get the report "Authentifizierung zusätzlicher Bereiche ist fehlgeschlagen” 
(Additional scope authentication failed).
The same happens when I delete and re-setup the account. It must be a Kmail issue 
because it appears on all my (Arch-) Linux machines with Kmail but not with 
Thunderbird.
Since I couldn’t find anything related in some Linux-forums (Arch, Manjaro Garuda or 
Ubuntu) or forum.kde.org/discuss.kde.org I’d really appreciate some help!

I’m Arch-Linux 6.11.6-arch1-1-x86-64 with plasma-desktop 6.2.3-1 and Kmail 6.2.3 
(24.08.3)

Regards

Andreas