Hi Dave... We had that happen last year after a long trip that included some "forest service dirt roads". There are 5 hold down brackets (or hold up brakets) located under the sink that screw (phillips) up into wooden blocks that are glued to the underside of the counter. I loosened all of them so the entire perimeter of the sink was down about a half inch and then ran a small bead of " 3M 5200 sealant/adhesive " around the edge, under the lip of the counter top and then tightened the screws to snug it up. I then smoothed out the excess sealant to form a moisture barrier to keep water from finding it's way between sink and counter top. After it was all done ( 36 hours to cure properly ) I added a support leg from the floor to the sink. We also do not travel with the covers on or anything in the sink to keep from having added weight bouncing up and down on it. Our last trip was 40 days in the Mountains of Wyoming, Montana, Idaho and Colorado with a good bit of it on dirt forest service roads (washboard and bumpy!) and it held up great, looks like new. Good luck!
Need to repair it post haste as we will be using the rig to take our daughter to college next week.
