try doing a slower pump and not a high setting mine did this when the suction was to high.

It doesn't even irritate it. I just know that having the wrong fit may impact pumping later on.

Maybe try putting coconut oil or nipple balm on the inside of the flanges, that way when your nipple rubs it won't irritate it as much. That's what I do.

I don't know what to do about it.

this is me too

I've used a 30.5, which pulls in areola. The 22 I just got starts out great, doesn't pull in areola. But once I've been pumping a few minutes my nipple swells and is rubbing the sides

What's the largest size you've used