Water Leak on Flagstaff pull behind

[MTN APPRAISER]

I own a 2018 Flagstaff Microlite 25' BRDS. Overall I am very satisfied with the camper except I have a water leak problem I can't figure out. Only during a downpour I have found twice recently water flowing from under the bathroom sink and across the floor. Both times this was only during heavy rain. As soon as the rain slows the leak stops. I have checked for line and sink leaks but no problem there. Directly behind the sink on the outside wall is the shower hose box. Is it possible I am getting a leak around the box or inner wall somehow? Any suggestions appreciated.

[Ken-m]

I believe your on the right track , that outside shower box on my 25 fbls would have been a leaker from new if I didn't remove it and seal it properly. Factory did a lousy job sealing . In fact if you have time remove and reseal everything you can . Also your max air vent needs to be sealed better , plenty of YouTube videos on it . It's where the pins slide in to hold it in place .