Tanks are basically mounted three ways in a TT.
Inside under a couch or cabinet, supported by the floor.
Suspended under the floor with a couple pieces of angle iron that hold the extended sections at the upper portion of the tank. Not good as it's just like trying to lift/carry a full pot in your kitchen using just your fingers to grip the rim.
Third method is to support the tank by the bottom edges on angle iron. If this method is executed properly there will be one or two "tie pieces" secured to the angle iron to keep it from spreading.
My 2018 uses the last method with 2 tie bars that arent going anywhere unless I pull my trailer over a stump or something similar.
My guess is that many of these issues occur with new designs and as the design matures the factory adjusts.
Would certainly pay to inspect this area even if one has to go to the trouble of lowering an edge of the belly cover. That or cutting an inspection flap and just taping it closed with Gorilla Tape.
My old 95 Terry had top rail supports on all tanks. I loosened bolts in slots, smacked rails so they were tight against top extensions, then tightened bolts TIGHT. Proceeded to go across the country for the next 22 years with full water tank and never had it come loose.
"A wise man can change his mind. A fool never will."
"Sometimes you're the dog, sometimes you're the tree"
2018 Flagstaff Micro Lite 25BDS
2004 Nissan Titan