Morning folks!
Seems like we might be able to help and you've done a nice job of getting us the main details we need to find WHICH RV you have!
We have some nice info online to let us look at things like plumbing without crawling all around and taking things apart.
I use it a lot on the forum so it is easier for me as it takes some time to get the controls handy! But you may want to look when I'm not around, so let me tell you a bit about a tool we have here:
https://catalog.winnebagoind.com/menu/Parts.htm
Choose which RV and then which group like plumbing, electrical, etc and you get down to a drawing of your RV where you can look through walls at what they hid in there!
Great for chasing leaks as we need to know where the tank/plumbing and such are to try to guess which is the bad guy!
Leaks are Tricky because water tries to run downhill and come out away from where it actually leaked!
Some info on how you are set up can help. Are you using the RV, in between trips, or stored? Got access to water and can you drain it somewhat easy? Tanks full or empty?
I took a quick picture of what your RV should have. Can you tell or show us where the water seems to show up? Is the RV kind of level or will the water run sideways to trick us?
One problem with using this is it only shows the plumbing if we choose that and that leaves me not knowing where the third compartment is??
Click this snip to get best view!
I put some hints on to let you look at things if it fits you. Sometimes being able to look at the drawings and the rV makes more sense of things!
But this is where the grey tank sets and I put question marks at places where grey might be expected to leak. Can you spot where the water shows up?
And then leaks are tricky because they may seem like the tank is leaking but it may be pipes going to the tank more often! Can you say if the water comes out quick after you drain some or do you spot it later after an hour or something?