Sudden behavior change

[Grroberts]

Hello,
Brand new to this website! Short backstory: I bought a hamster(she is a dwarf hamster, although I’m unsure the specific type.) several months ago and had the same cage until August 15th. Previous cage was a 2 level Ferplast cage with bars. I believe it was just over 420 square inches. She was constantly bar climbing and chewing and I learned that could be a possible stress call. So I bought a 40 gallon terrarium(intended for a turtle, but is amazing). It measures 648 square inches and is obviously deeper and wider and just plain amazing. Now, Pepper is very skiddish and runs and hides whenever she sees me. She no longer takes treats from me, actually I can’t see her for more than a minute or two before she runs and hides. I thought it was great because she suddenly started to burrow a lot, and very deep and built tunnels everywhere. I’m unsure why she is acting so differently now. Is it because of her housing change? Because it’s all glass now? I’m stressing because I care for this hamster so much and want it’s short life to be a good one. Any thoughts to help me out? I tried to post photos but they are “too large “