f5 r5600 appliance issue with adding trunk to vlan

The issue/error message is back again :(
We need to setup different VLANs in dedicated partitions/Route Domains.
Therefor we created first the VLANs on F5OS and assigned them to the tenant.
Then these VLANs will correctly shown within the tenant, but by default in the Common partition.
We deleted the VLAN in Common, switched to the required partition and tried to recreate it there as well using the exact name like in F5OS.
But then we get again the ERROR: Unable to find interface object for configured trunk member 3.0
Where is this coming from and how can this be fixed?
Thank you!

Regards,
Stefan :)