• BDS 1.16.101.01
• Server 2019

I was fishing, and started taking damage from nothing.

After swiping my sword around for a minute, I saw a drowned flashing red every time I was getting hit.  He was taking damage from thorns.

My son also told me that he was taking damage, and couldn't find what was hitting him.

And a third person said they started taking lots of damage (they thought they were lagging). and then died.