Floor didn't make it through the winter

Very common occurrence in rv's several years back. Lino is edge glued at the factory and expansion/contraction causes these huge splits on days when rig is cold then warms up too fast or vs/versa. Cut out old lino, and have replacement material glued down. This has nothing to do with anything you have done, and everything to do with a residential material being used in an outdoors setting. Ours happened in 09 along with hundreds of others at local rv dealerships.

Daryll