S390 switches can support a total count of 1000 VLANs per stand-alone switch or switch stack. VLAN ID 1-1000 are configured by default.
It supports VLAN IDs > 1000 but only support 1000 VLANS, VLAN ID 1-1000 are configured by default, and when mangement vlan is >1000 there are 1001 VLANS. We got it confirmed på Meraki Support and its a known problem.
We found a workaround.
Set managment vlan on the switch to 1 and Switch > Configurere > Switch Settings > Management VLAN 1 before you move it.
Thanks for yourtime