Had same problem, water leak from shower hose fitting ,close pocket door, should have access plate from wall behind sink, water was running down inside shower wall out onto floor, replaced moen valve with new symmons valve, they used silicon on hose fitting and shower valve, water connections are pex with crimp rings.
Plastic elbow on shower hose connection. I replaced Plastic fitting with 1/2" brass elbow, and male pex adapter also.