I s it leaking? The the whole shower pan and drain should be tested.
To test put a stopper of some sort,I just use plumbers putty to cover drain.
Fill to 1in below curb and look for leaks.Can be caused by stopped weep holes
I take it this is a tile shower stall.Cap shower head and turn it on to see if valve leaks.Splash water on walls to see if that causes a leak.
These are test that I would do for a tile shower .