Inconsistent nipple confusion?

So my baby was EBF for 6 weeks, then mix of BF, pumped bottles, and occasional formula. Now he’s 2 BM bottles, 2 formula bottles while I am at work and nursing the rest of the time when I’m home. We are currently at 14 weeks... and in the last 1-2 weeks he has what I can only think is inconsistent nipple confusion. Most of the time I go to nurse him and he’s great! Latches, eats anywhere from 20 minutes on one to 10/10 split of both. But then randomly he will decide to FLIP OUT like my nipple is covered in poison, and will either not take it and we make a pumped bottle or I put on a nipple shield (which is just like a bottle nipple) and boom he eats like a dream. WTF? It may not happen for days then all the sudden the does it, then eats great again a few times and then happens again. It’s like sometimes he just FORGETS how to nurse.... what does this mean? Shy of using a nipple shield every time (which I sometimes feel makes him get less) or just switching to bottles all together... idk what to do!