I thought I found the leak. It seemed so obvious, however one might say that forest river would never build a shower stall this way. When I was checking the faucets for leaks I pulled the entire faucet off the wall as a unit to check the connections and pipe. This time I disassembled the faucet by removing the knobs and front plate and when I did I discovered unsealed holes leading behind the shower wall. I guess that that wasn’t unreasonable and probably predictable however when I examined the area where the shower hose connected to the faucet, an unsealed gap around the connector existed. I don’t know if the faucet was installed upside down ( if the connecting shower hose was fastened underneath instead of on top it probably wouldn’t have been an issue) or if a part sealing the area was omitted during installation however I sealed the area behind the faucet as well as the bottom of the connector. If this product is installed in other units as in mine, it can’t help but leak. Well guess what! Still leaks so we're still monitoring. I wanted to share this for others to consider. See pictures
Tried the suggestions of spraying water on different sections of the shower and no leak. placed 2 inches of water in the pan and got in and moved around, no leak. let the water drain and looked under the pan at the drain, no leak.
When I purchased the RV, the shower floor was like a trampoline so I built a sub floor to stiffen it up. maybe I moved something just enough to create the leak although there was no visible evidence. I removed everything I installed so I could clearly see under the pan. took a shower and no leak. All I can do at the point is continue to monitor.