I am not a motorhome guy and maybe someone who is can be more helpful.
However, if it was my camper, I would definitely remove that panel and start troubleshooting right away (or get it right to a dealer if you are unable). Water leaks are nothing to fool with.
Those screws need to be replaced with stainless steel equivalents anyway before the panel comes off on its own (or the screws break off when you finally do need to remove it for something).
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW