Thicker walls in model producing fine horizontal lines?

So just wondering if anyone else has a take on this. I printed a small head and first few prints came out perfect. Nice details, no imperfections. My recent prints are good though I have noticed very fine horizontal lines upon close inspection on the left side mostly. One thing I realised is that the walls are much thicker on these latest prints. So do thicker walls mean the printer slightly struggles with the peeling a bit more hence why the lines are showing?

They’re not terrible, though enough to interfere with the fine details of the head.