Slight dripple of water from side sliding window at dinette

2004 Fourwinds 5000. I made sure the outside drip slits were clear by spraying hose into each slot to get out pollen/leaves that tend to build up over time. Only on heavy rain do I get a few leaks running down the paneling into the dinette couch. Outside looks normal but think its just overflowing along the window guide as the outside water tries to drain out the slits and some overflows into camper. Should I try and remove interior screws holding window in and try a bead of sealant? Seems the next logic step but wanted some expert advise from the knowledgeable panel on this site! I've heard its never a good idea to seal the outside windows and drain slits completely, but verification would also be nice to hear. Thanks in advance!