Diagram symbol definition and software

Hello, I recently had a copper pipe leak in our bathroom and had someone do a repipe with pex do prevent future problems. Right after I finished closing all the dry wall, I noticed that in the bathroom, right where the sink used to be (opposite side of the leak), there is a wet/dark spot on what appears to be the foundation. I opened the drywall again because I figured I must have drilled a screw in the pex, but everything seems fine. The wet spot seems to be by a drain pipe. There is no smell whatsoever from what I can tell. It's hardly wet, this morning I could feel it and I had to feel multiple times to be sure it's not just dark. When I opened the drywall, the dust from cutting it went over the spot and now it doesn't feel wet anymore, but still looks the same. I don't think it used to look like this, I think this is new. When putting my hand in that opening in the wall on the picture, I cannot feel any wetness whatsoever around the pipe or on the wood, no where. What are possible explanations for this, and what would you do to proceed before jackhammering the foundation open? Thank you LA DIY

Hey everyone. Thanks in advance for any answers. I live in a two story condo, on a slab. A week or so ago, I noticed the sound of water running in the pipes consistently. Almost sounds like the water running when someone is taking a shower far away from you in the house. It's not a neighbor, as this is a 24/7 sound now. I have a water heater in the pantry in the kitchen, and the downstairs bathroom is close-by. You can hear the sound of water running and in both the bathroom pipes under the sink and the pipes over the water heater, a slight hiss every 5-10 seconds. As I sit in my living room, the sound is just reminiscent of someone running the water in another room. Just the sound of water running consistently. I can also hear the hiss from here every several seconds. Any ideas of what the issue could be?