Bumper Hitch Question

I am pulling my 27ft Jayco bumper hitch trailer with my 2500 Dodge diesel truck, we left gulf shores early and were almost to the northern border of AL with no issues. The old Dodge is humming along.

we drive a short distance through a medium rain shower, then pull into a station and fill up with diesel,

Problem:
when I pull out of the station I heard this loud noise coming from the trailer wheels or hitch, hard to determine with the windows up and still a light rain falling. So we pull into a local parking lot and try to determine the source of the noise, before we get back on the interstate.

I back off a couple of turns on my sway bar clamp and the noise when away, but I did not want to drive with it loose.

I was glad the noise was not a trailer brake dragging

so I just tighten up the stabilizer bar and drove on.

question: why did the stabilizer bar start making this (loud) noise each time we turned after the rain shower???????

when we parked that evening, I took the stabilizer bar apart and cleaned the bar as good as possible with the cleaners I had on the truck, must have worked as I no longer heard the noise.

so what would have made the noise? dirty bar getting wet?

this ever happen to you guys?
you do want that bar tight as it helps to keep the trailer from swaying when a 18 wheeler goes by at 75-80 mph.

thanks for any input.