I have seen this in my bedrock realms world as well. The only addon I think we're running is a portal one to allow teleporting, which shouldn't be causing these water glitches in chunks far away from these portals. I don't think the owner has (let alone knows how to) edit the world in a third party program. We've only upgraded to the creaking update, as to the question about upgrades.
We're seeing glitched water just like above. I've even seen big air pockets inside of water bodies with water sources running down the edge next to air blocks.
See also MCPE-189293