Hei @MrChris ,
Microsoft support emails will have their manager's emails in their signature, you can loop them and ask for an escalation or transfer to a different timezone.
As @Anonymous suggested above, you can also get in touch with your regional manager or relationship manager to get it escalated.
About your issue,
Start with permissions, make sure that you have contributor or above permissions on the source and target resource groups.
Next, check the status of the resource X that is stopping you from migration. I am assuming it is a network card as you are moving a VM, it can be disconnected from the VM and then reattached when the VM has migrated.
The idea is to decouple the resources such that there is less dependency on other resources, starting with creating a new network interface and attaching it to the VM, this can be from any stable network and even from a temporary network that can later be deleted. This will allow us to remove the existing network interface from VM (not delete just detach) and just like that both resources are free to move.
Now that the resources have moved, it is possible to reattach the network interface and remove the temporary interface (and delete it too ad it was temporary)
More information, here
On another note, having networks in a different subscription may not be the best architecture for operations. Subscriptions are constructs to isolate cost and a network is a shared resource, so you may want to look into landing zones
Please mark it as an answer if it helped you!