After having a more detailed look at the problem, I recognised that it is not fixed.
Here the error message:
root@srv02:~# pct set 1001 -net1 bridge=vmbr0,hwaddr=02:00:00:51:cd:b1,name=eth1,type=veth,ip=178.33.157.22/32,gw=149.202.210.254
RTNETLINK answers: File exists
command 'lxc-attach -n...