Soft spot in floor

[Luke Croll]

Good afternoon. I have a soft spot in the floor of my 2011 Laredo 300RB. It is right above my grey tank and has been getting worse little by little. The spot is not much bigger than 2'x2' and everything else around it is very solid. When driving this spot in the floor is covered by my super slide. It is right next to my front living space heating floor vent. I initially thought it was just shoddy construction right around the vent but it seems to have gotten worse. My kitchen sink is w/in 3' of this leak but I assumed that it just dropped right into grey holding tank. Any help would be lovely. I am not shy about pulling up flooring or dropping the bottom either, I am just wondering if anyone has had a similar problem with their unit. Thanks again.