Need help - Leaking roof - Event Date: 28 Oct 2020

+1 to JR, did not see that post prior to my reply.

Welcome to the forum and congrats on your 179.  I have experienced the same water intrusion problem on the slide side of the counter top of my 2019 179.  I had the trailer in at the end of the season last year for some warranty work at the dealer where I purchased it (the work was replacing a side wall on the slide out because the exterior fiberglass had delaminated from the wall) but at the same time I told the dealer about the water coming in on the counter top after a rainstorm and the water was running down the wall from the interior bottom frame of the window.  They felt that the rear window gasket had not been installed properly.  They took the rear window apart and sure enough the gasket was what was causing the leak.  They repaired it under the warranty work.  Don't know how big a job it is or if it can be done by an owner or not (the need for special tools).  You may want to do some youtube investigations.  That is where I would start with your water leakage.

Is your roof spoiler directly above the leak? The spoiler with lights at rear of RV.