Most trim is initially installed with putty tape or butyl. I'd be willing to bet yours is. They'll install the trim with the putty, then cut off the excess. Then some, not all, come back and do a perimeter sealing with another sealant. My preference has always been Geocel Proflex. It's not your average caulk, and is not silicone. Got a picture of an area you're talking about? Corner trim maybe?
John and Rebecca Dickson
Emma-8 / Little John-5 / Iva-1+
2013 Ford F-350 Lariat FX4, CC LB PSD, DRW
2015 Jayco Jay Flight 28BHBE (#8)