I lubed the zipper before first use ;-). It’s the metal zip though, maybe that is why it’s a bit more involved. In any case, not a big deal as I usually do not dive alone.
I don't usually dive alone, either. I just have a "thing" about being self-sufficient. I hate asking for help if I don't need to.
Anyway, yeah, I have zipped metal zips for friends. Those things are a lot harder to close.
Maybe instead of a back zip with metal next time, you should consider a front zip with plastic...