2014 Dutchmen RV - basic roof sealing question

Basic question here...but I just bought this used Trailer. It's in mint condition...always covered and minimal use. But given this, the previous owner never had the need to seal around the vents or stairs on the roof etc. I'm wanting to do that basic maintenance since it's almost 10 years old.

The original sealant is very gummy. I'm assuming it's lap sealant but I don't remember it being so gummy on my previous rigs. It's lifting up around some of the edges, especially around the vents.

Can I just put new dichor lap sealant over the top? Is this normal?

I've attached some photos. The existing sealant is black from wear but you can see in one pic white underneath. It's gummy, almost the consistency of butyl tape.





Thanks for the advice!

Moderator edit to show pictures.