Running hot and cold

My (29m) gf (27f) fell hard and fast, but recently I’ve felt like she’s run hot and cold during our visits. At times she is very loving and affectionate, and has told me how invested in the relationship she is. At other times, she has openly questioned whether she should be in a relationship, or be monogamous. Just yesterday she told me that there are people near where she lives that will make her happy and be good partners, and although I think that’s true for everyone, it was confusing and sucked to hear.

I’ve also noticed that her moods have shifted quickly and without warning, often in the form of an icy silence or coldness. I learned not to ask whether she was ok, as that annoys her, but she later admits she is angry with me about relatively minor mistakes (forgetting to run the dishwasher or sleeping in too long on the weekends, for example). The relationship has not felt like a safe place, but the affectionate moments are intoxicating. I feel very unsure of us, but don’t know how much of this is the distance versus compatibility.

TLDR: gf running hot and cold. Is it distance or compatibility?