I clearly remember that I had the same problem, same reason (post-Qubes formatting) and that I resolved it in Windows using disk management at the end after diskpart which at some point failed. I remember I successfully deleted LVM partition in disk management after semi-successfull operations with diskpart and was surprised when I saw “unallocated” space instead LVM partition.
At least you can start new Qubes install, this time do not choose LVM and later there shouldn’t be a problem to delete and then format disk.
Same Problem a bit complex situation. I happened to install it on my Primary SSD and unlike above DISKPART wont list the SSD at all.
Here’s the link to my topic, can someone help please : Format SSD - Unable to view disk