The armor I was wearing was full netherite armor except the chestplate, instead I was wearing elytra and my boots had feather falling max. That is about it. I was in the nether where there was some netherrack and below it was air. So I was on the same level as the air, but I could still walk into the netherrack and started suffocating. (The version is 1.16.220.02, cause I can't seem to get 1.16.221, so I don't know if it is fixed.)