Water under shower floor caulk

Shower walls and floor are ceramic tile and caulked around bottom. That caulk keeps getting moldy fairly fast, so I removed caulk (this is second time in a few years) and was going to replace. I noticed there is water in the gap on one wall – wicks up with a paper towel- can't see it. Does that mean there is a problem or it that normal? Walls are grouted – there are a few small areas missing grout and I was going to patch that with caulk. Could that be the source or at the drain? Wondering if I need to call a tile guy. No water on adjacent walls. The house has a crawl space foundation. I can keep trying to dry it out, but wonder if I need to address some other problem. Thanks!