Mold issue

Hi Guys, so I’m quite new to resin and I’ve bought a three piece cake stand silicone mold, in the centre it has a little piece of silicone sticking out so you don’t have to drill a hole. The problem is, as the resin sets, a circle of resin seems to appear around the part in the middle sticking up that doesn’t match the rest of the piece, although it is still completely level. It’s hard to describe, can you add photos here anywhere? Thanks Jenna