Have a tub/shower combo... walls are seamed on the inside corners. Looks like 3 - piece wall unit. Originally seemed well fitted but I caulked it anyhow. Now, after 1.5 years of use have a leak on the pipe side, seeping out where the surround meets the tub. Constant drizzle when water is flowing from shower head and/or being splashed. The fixture for the tub spout and water lever were not caulked. Is that where my leak is?
You could be leaking in several areas. Caulking is not permanent first off, it does need periodic maintenance pending use, check the cualk carefully and remove and replace as needed.
The spout and trim plate(s) for the handles should be caulked as well, but not 100%, leave them open on the bottom so as any trapped or leaking water in there has an escape route.
If all else fails, start with the easiest items, check the teflon wrap around the threads on the shower head arm where it goes through the wall, then the spout (if threaded, check the teflon, if slip on, check the seal). After all that check the connections where the water supply meets the valve, both in and out sides.