The bug
Since the new parity changes are coming to Java Edition, there are 5 new gamerules from bedrock edition, one of them being fallDamage.
Theres a bug with it at the moment when updating other worlds to the latest snapshot. It seems that fallDamage automatically sets to be "false".
Here are 2 different clips of differences before the parity came to Java (19w35a) and after when they were implemented to Java (19w36a)
I didn't use the command since I made a test world before 19w36a to show that this glitch exists.
NOTE: When creating a new world with the latest snapshot (19w36a), fall damage will happen as nothing happened. It only occurs when updating other worlds!
Thank you for your report!
We're actually already tracking this issue in MC-160464, so I resolved and linked this ticket as a duplicate.
However, that ticket has already been resolved. Depending on the resolution, that can mean that it either will be fixed in the next version, or that it is not considered a bug and won't be fixed.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
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