Hi,
I have the exact same issue in my lab with vCD 10.1.1 after a failed vApp deploymenet. I tried to delete the vApp and/or the VM with Powershell or the API and no way found.
I also tried to update them from the Posgres db without success, (last time I had such an issue it worked fine on 9.5)
Postgres commands you can try to fix the status of you VM/vApp to delete them :
sudo -u postgres psql
\l (show all database present on server)
\c vcloud (connect to database vcloud)
select * from vm_container where name = 'VMNAME'; (in the result you can find the SG_ID and VM ID for the following command)
update vm_container set creation_status = 'RESOLVED' where sg_id = '4dc82adf-2a76-477d-xxxxxxxxxxxxxxxx';
update vapp_vm set creation_status = 'RESOLVED' where id = '2c5dff0b-6ef4-4aa8xxxxxxxxxxxxxxxxxxx';
Please note that it's totaly unsupported 