Changing size of thin tubes and domes

I have recently gotten my first hearing aids (Danalogic Extend). I was prepared for a lot of getting used to them and frustrations but actually I really liked them right away and was excited by all the things I could hear now.

Only problem was the domes were really annoying, itchy and constantly needing to be pushed back in my ears. Constant like every few minutes at times. I went back to see if different domes would help. I was given an assortment to try (all open domes), and they swapped my thin tubes for shorter ones. The audiologist made no programming changes at that point, but before leaving, I asked if my speech in noise programme could be more forward focussed because I was still really clearly hearing people speaking behind me.

As far as I know, these are the only things that have changed. This was two days ago, and since, I’ve been getting headaches and nausea with fairly short wearing times. I didn’t have this at all before. Would changing tubing length or dome size need reprogramming? Is there any other reason I would suddenly be struggling with them after 1.5-2 weeks of success initially?