started my own server. server and client have level up mod, when i open the gui to pick a specalization while on server i can click any of the three options and click done but nothing happens, no levels are spent and i cant get to the next level up menu to start spending levels.
If i am doing something wrong please let me know, I have nothing to submit to show this as it not a crash

Mod and Forge versions are a good place to start. There are a few versions of Forge where player capabilities were outright broken.

14.23.2.2655 forge and level up 1.1.19 level up. What version of forge do you know still works correctly on server? thank you for the quick response

The latest Forge server I've used where it works is 14.23.2.2624

Issue is reproduced with forge-1.12.2-14.23.4.2749 + Level Up! 2-1.1.22-1.12.
The workaround is to reconnect after choosing your level.
Also, the initial specialization menu comes back every now and then, not sure why.