Thanks for the responses everyone. To address a few of your questions, YES, I absolutely plan on removing the hatches, cleaning and removing all of the old sealant and reinstalling with new. I don't want to have to do this again anytime soon and certainly don't want any leaks!
It appears to me that the factory (Northwood Manufacturing - Arctic Fox Truck Camper 990) has used a clear silicone to seal some of these hatches? Some of the other vertical items appear to have a white non-hardening caulking of some kind though? Anyway, it's the ones that appear to be silicone that I am needing to fix as the sealant is cracking...
I have pix but can't seem to get them to post here... ?
Thank you.
2015 Chevy Silverado HD 3500, 4x4, Diesel, crew-cab, long-bed.
2019 Arctic Fox 990