Is it possible that what you are describing as glue is actually clear
silicone caulking? Is it pliable? If so, you can probably cut the top
loose with a sharp knife.

If it isn't clear silicone caulking, I don't have any suggestion for you,
other than to try different solvents - start with water and go from there.

Honestly, I don't know if it's clear silicone caulking. I have very
little knowledge when it comes to adhesives. But, it's not pliable.
The top glass plate is firmly attached, and it can't be moved even
with great force.