Delta Pro Smart Generator Adapter difficult to remove

Yesterday I did a test with my Delta Max 3 Plus and a Delta Max 2 Extra battery, using the smart generator adapter successfully.

Today I decided I was going to remove the Smart generator Adapter to look at the new pin configuration, and I was not able to remove the adapter.

I did press the tab but it still did not release. Rather than break something, has anyone experienced this before I use too much "pull" and break something?

Any tricks to remove this or is it just tight because its new?