can confirm that with libnextcloudsync0_3.1.1-1_amd64.deb and nextcloud-desktop_3.1.1-1_amd64.deb from debian bullseye it works again.
can confirm that with libnextcloudsyn c0_3.1. 1-1_amd64. deb and nextcloud- desktop_ 3.1.1-1_ amd64.deb from debian bullseye it works again.