Maybe I am confused, but 2 5/8 is an unusual size. I am pretty sure I tow with 2 5/16 and that is the standard size. Apologies if I have it backwards.
Expect it was a typo, if you have to jump on the hitch to get it to release, it is probably under tension and backing the tow rig up a quarter of an inch will usually release it. Or you may have to pull forward ever so slightly. Figure out which way the problem is and take correct action. It likely won't be the same every time.
It is also possible that the hitch mechanism is bent slightly causing this. The one I had that was bent was not possible to straighten so I ended up replacing it. It was not welded (utility trailer) so replacing was easy. TT usually have them welded... making it harder.
The latching mechanism may be adjusted too tight also, making it hard to unhitch. Be careful messing with that, too loose and you have other issues.