Longtime ago a "recycle bin" was introduced. You have to purge the bin to get the space back. Within the group manager click on the lower left "tools?" I have no grpmgr in front but iam sure you will find it.
Otherwise are you sure you havent delete a thin provisioning volume? Maybe it wasnt full.
:Confused: oops! I never noticed that LOL. Well it's empty so I guess with was a thin provisioned one.
I'll let it go at this point. I was overthinking and thought I would have to SSH in and run a bunch of commands
You are very welcome. It doesn't matter if a volume was thin provisioned or not. Works the same way.
TP vs. Classic volumes are just how the space is allocated. So once written to they will end up in the recovery bin automatically