Same issue with our shamrock...
Pulled up the U-Channel on the inside, pulled the canvas out, cleaned everything up. Clear Lexel in the channel and reinsert the canvas...
Keep the poles loose to not pull the canvas and keep working the canvas in.
I drilled and added screws through the U-Channel to keep everything secure..
2 years later its still holding.
2015 Shamrock 21DK
2005 Silverado Ext cab
Nights camped 2019.....all of Em...Homes a 2001 Sea Breeze 36' 5 ER