I have no experience with this issue, but my guess would be to try and remove the strip that covers the seam. Re-staple the wall and we-apply the seam tape. You may need double-sided tape to re-apply it.
2013 Ram 2500, 6.7 CTD, CCLB 4x4 in True Blue.
B&W Turnover Ball, Andersen Ultimate Hitch (v2)
2016 Eagle HT 29.5 BHDS Picked-up 4/1/16
2007 Rockwood ROO 21SS - SOLD