My aquatic mobs drown... underwater...

For some reason my custom water mobs drown underwater. It's not only really confusing but also really irritating.

And yes, I've checked "Check if this entity is water entity".

Yes, I've checked "Can breathe underwater".

Yes, I've given it mob AI.

Yes, I've made it a waterCreature spawning type.

I've even set the creature type to WATER just to make sure.

The only fix I've found so far is by checking the "Immune to Drowning box", but I shouldn't have to do that if I check "Can breathe underwater", should I? (Not to mention the drowning particles still appear)

I've also noticed this only happened in the most recent update (2026.2) so this is definitely something to consider fixing. I apologise if I am pushy.