Trouble with my floor

before fully taking out the lino, I would first try removing just a small "cut out" (ie. just larger than the screw / bolt... size of a quarter or so) in an area that is the least visible. Use a sharp box cutter or equivalent. See what up with the underlying fastener. If you can tighten it down or whatever (ie. replace it with something better). Then glue the cutout back down. I suspect the fastener let loose from what it is screwed into or broke. Actually, what is likely is those fasteners weren't fully set to suck down the subfloor to the frame. Then with time and travel, the subfloor sat down leaving the fastener "proud" / high.

If that doesn't work, then you are likely left with removing the lino to address the issue although you might be able to "patch" with some "board like" equivalent pattern running accordingly.

If you can not get to the bolts from the bottom, then it would seem the only other choice is to pull up the linoleum and see what is the issue. Overall not a good position to be in. This why I gave up on Airstream, they have plywood floors and ours had soft spots within 3 years of ownership. You would think marine grade would be a minimum standard?? They all leak at some point. I hope this works out better than it looks. best of luck..

Here. I'll help with the pic.
My guess is that the frame is flexing and stuff is coming apart. Are the cabinets holding firm to the wall?...misaligned counter top edges with the wall? Windows harder to open?

by the way - we have that same dog bowl rug...