Caulk/sealant on top of rain gutters.

[MandK]

Up on the roof today checking things over. It looks as though the caulk or sealant on top of the rain gutters is drying out and cracking. I’m not sure which sealant to use here. The awning rails are sealed on top with clear silicone type sealant, probably Trempro 645, but the rain gutters appear to have what looks like a bead of white latex caulk. It is similar in color to the dicor self leveling sealant used on the roof material but doesn’t feel the same. The two materials that the caulk has to adhere to are the roof membrane and the plastic rain gutter. Does anyone know what is on there and what I should use to reseal with? Thanks.