here are some pics

Hope these help millworkman ! Tried to get as much of the pipe labeling as I could

I'm not a pex expert, but I have used that style of crimp (Apollo brand) and I haven't seen that type of fitting, with the blob at the end. In a quick search for crimp images, I can't find that one. Also, I think the print on the pipes in the photos you posted are the approvals info. Somewhere else on the pipe should show the manufacturer. I can almost read it in the fitting pic.

Not familiar with those fittings either. You need to find the PEX manufacturer info as Seabornman states. Look more for the name.

It looks like a Viega press fitting. I can't tell from the photo how much space there is where the elbow fitting is, but one of the main advantages of using PEX is that you can eliminate elbows. So I wonder why there is an elbow fitting at all.

I was able to make out the word HyperPure on blue piping. Would this be the brand?

Yes, HyperPure is a brand: 100 year warranty! Maybe you should start with them. I suspect some problem with the fittings.

Not a huge fan of the idea of pex, but my whole house has it. Zero issues in 10 years.

The problem isn't PEX - it's been used for decades and has a proven track record (as well as known issues such as the presence of rodents, high chlorine and UV exposure that would be a reason not to use it in certain applications).

The problem in this case is defective materials or installation.

Ignore the comments about "why is there an elbow at all" - it doesn't matter. Using PEX does allow for fewer fittings - which reduces time, cost and opportunities for a leak. However, the presence of an elbow is not evidence that PEX was improperly installed (leaking fittings is another matter).

Call the GC who hired the plumber and expect them to make it right. Of course it will be very expensive for the GC/plumber, and you should expect a lot of pushback - but keep after it. Start by calling and letting them know / inspect / etc. Then escalate with a written demand and only if they aren't sitting down to the table should you mention an attorney.

If it's defective materials, the plumber is going to go after the supplier. BTW: If that's Viega Pureflow pipe and fittings (looks like their fittings) it has a 25 year warranty and within the first 10 years will also cover drywall, painting etc. If it's a mix of pipe (HyperPure) and fittings (Viega) from different manufacturers, the warranty probably doesn't apply.

Look, we the consumer, are paying significant amounts of money for professionalism in the trades that oftentimes isn't really there and seems to completely evaporate when there's an issue. We rely on their expertise when they make decisions on materials and methods (like maybe you don't mix pipe and fittings so you have a warranty). We regularly hear why installers are right to be billing $100 - 150 a man/hour because they are highly trained professionals - and the truth is that some barely know which end of the crimp tool to hold.