This is still a problem!
I tested it in singleplayer 1.14.3 with mobGriefing = false
The sheeps eat the grass and the grass dont dissapear.
With this bug it is possible to create op wool-farms when the gamerule is set to false!
I have the same problem and the same error.
It only happens with converted worlds (I tried two different worlds where the problem occurs).
This is still a problem!
I tested it in singleplayer 1.14.3 with mobGriefing = false
The sheeps eat the grass and the grass dont dissapear.
With this bug it is possible to create op wool-farms when the gamerule is set to false!