Blueprint rules for references to other objects

TLDR: Local reference types don’t seem to actually keep references.

In my GameMode class, I have a Map, TradeSkills.
I also have a function library my other blueprints use for handling tradeskills. In one of the functions, I needed to operate on the GameMode TradeSkills map a lot, so I set a local variable to reference it and work off of the local map.

At this point, I would expect if I add entries to the local map, it would actually add it to the tradeskills map. This doesn’t seem to be happening.

This function is being called from the GameMode itself (for initialization), so I know it’s happening on the server.

Are there not two types of variables in blueprints, reference types and value types? I would expect a MAP to be a reference type. Or, is there some aspect of GameMode I am missing?