Hi, I have a 16-month old “new construction” townhouse and a there is a strip of about 2 feet of engineered hardwood floor in front of glass doors/panes that go out to a 4th floor flat roof terrace that has been reading very wet (beeping and red light and "OL overload") on a moisture meter ever since Jan 11th (which is when we first ran a moisture meter across it.)

• The hardwood floor itself is not cupping (so the developer is thinking the hardwood isn’t wet).
• The developer has cut through the sheet rock ceiling in the room directly below (3rd floor bedroom) and they ran the moisture meter along the "bottom" of the Advantech subfloor and it reads dry.
• Video of the moisture meter reading is here: https://youtu.be/3esBjP6cMhs

They seem stumped so I’m hoping someone here might have some advice/guidance I can pass along to them.

In case it's helpful here’s some additional context:

• The floors are Shaw Bluebell Oak
• The terrace has “bison wood” tiles on pedestals that bring the “height” of the terrace parallel with the threshold (see photo). If the bison wood tiles aren’t present there you would step down a couple of inches onto the roof membrane (not sure if that’s the correct term for the stuff that looks kind of like vinyl).
• About 5 weeks ago when they were trying to figure out why I had some water dripping from the ceiling of my second floor kitchen (2 floors directly beneath this), they did find that a part of the roof membrane had bubbled up (see photo) and they fixed it.
• They also saw a couple of holes in the strip of siding under the threshold of the doors but they said those holes didn’t penetrate the Zip Wall flashing.

Thanks for any advice you may have!