Figured it out, reposting:
Week 1: Pulling vinyl flooring
Found the water damage! Plenty to go around! Luckily for me its only one panel of subfloor. Easy fix. The aluminum frame underneath is fine, so a new sheet of plywood and we're good as new! The A/C Unit above the water damage was the likely culprit here, so that warrants a follow up.
Dinette set had to be removed, needed access to all of subfloor. Plus it was tacky.
Here's the floor rot
A/C
Dinette
