PEX Manifold issue - request advice

2 issues. I live in Florida. We have a concrete slab as our foundation. In our garage the water enters the home from the slab into a PEX manifold.
One of the lines coming off the manifold looks corroded of sorts. It’s a line that is used daily- as it runs to the kids bath.

Question #1
1) What is happening with it and how do I correct the issue?

The second issue (I think or perhaps it’s related to the first issue) is recently I have noticed what appears to be mold growing on either side of the wall surrounding where the water enters the home from the slab and runs up into the wall to connect to the manifold.

Question #2
2) What could the cause of the moisture most likely be? Could the lone be split where it exits the slab? Or is it leaking where it connects to the manifold? Or perhaps it’s related to the first issue and the simplest fix is to reconnect the line to the kids bath and see if that solves the issue?

Any professional help would be appreciated.

Thank you.

I would assume there is a leak behind the drywall. I would cut that open and have a look

Also, regardless of what you find behind the drywall and baseboard, that mold has to be attended to, as you probably already know.

As far as that one pipeline connection, with what appears to be hard water residue, I would suspect a water seepage. I would clean it up and watch and feel for water seepage frequently. It could be just an occasional drop that evaporates and leaves those deposits.

The connection and the manifold are plastic so no corrosion, but i am going to say it is leaking. Easy way to tell, clean it up ( toilet bowl cleaner or coke cola will remove the buildup easy), dry everything, then wrap a piece of paper towel around the connection. Check it everyday, especially after using that bath. If it is wet you know that itis leaking.

The other pics look like you have a leak in the wall or at a connection point. Cut a decent sized hole in the drywall ( 12" x 12" or greater. It will be easier to patch later with a larger hole so dont be scared by that).

Wear a mask! It looks like you already have black mold from the picture and you dont want to risk breathing in any that become airborne when you open the wall up. From there you should be able to find the source of your leak. If not, your going to have to expand your search.

It can get difficult if the leak is at the connection as water will run down the pipe. If you need to open up additional walls or areas just remember to make a hole big enough to see what you need to see.