Minecraft villagers are constantly getting affected by invisibility

In my village, my villagers are constantly becoming invisible, even wandering traders are invisible, only their llamas are there. That said, they always reappear after a few minutes. I thought that witches might be the reason so i did a test. I kept and surrounded a village with walls and lit up the place, yet some of the villagers are still becoming invisible. This issue is really annoying, because I can never find the villager I want to trade with.