This was an issue for us when we had 9.1.2. And I think it was a known bug?
I found that if I then manually deleted the first couple of devices subsequently, then the bulk process would finally go through.
This is no longer an issue with 9.2.2, thankfully.
EDIT: And 20 days later... here we are with 9.2.2 facing the same issue. Grr.
still same problem here. try to do the things written here https://kb.vmware.com/s/article/50116392?lang=en_US but no luck. any news?