What is happening with my vanilla bean?

Hi everyone, I took your advice and repotted my vanilla and changed the medium. It’s doing super well, and I have had it enclosed in a little dome on a heating pad so it could retain some humidity and heat here in NJ since it’s freezing. It has shown awesome growth so far with a new vine coming from the soil. My question is this fuzzy vine appeared from the top and I’m not sure if it’s mold or something. Is that even possible? I haven’t opened it up in probably a week or 2.