Statement during Migration of a VM from one PVE-Node to another

Hi all,

I'm new to Proxmox

Today we updated our three proxmox servers to PVE Version 8.4.1

During the update, because there was a kernel update available, wie set one PVE Node to maintenance mode.
During the monitoring of the migration process we notice the following to lines for each VM target to be migrated.

....
Use of uninitialized value in string ne at /usr/share/perl5/PVE/QemuMigrate.pm line 1324.
Use of uninitialized value $last_vfio_transferred in string ne at /usr/share/perl5/PVE/QemuMigrate.pm line 1324.
...

Don't know if this is only an Information, a warning or critical notice.

Unfortunatly Migration of a VM from one node to another takes ages than seconds.

I set migrate: insecure in /etc/pve/datacenter.cfg to speed up migration but with no noticable effect.
All my three nodes have an uplink with a Dual 10G Ethernet Adapter and are connected to the same Switch

Any hints to look at for isolating a potential bottleneck?