Upgrade with kubeadm 1.28.4 to 1.28.10 (or 1.29.n) etcd fail

Cluster information:

Kubernetes version:
bare metal
Installation method:
Host OS:
debian 11 VM on proxmox
CNI and version:
weave 2.8.1

when kubeadm upgrade apply v1.28.10 the upgrade get stuck and timeouts with:

[upgrade/apply] FATAL: failed to create etcd client: error syncing endpoints with etcd: context deadline exceeded

any hints? I see no logs, no errors… just the timeout. Not the first time and I normally would solve this with recreating the cluster … but there is probably a better method?