Just tried it and it seems the issue is worse: the horses take fall damage from 1-2 blocks high from jumping, but not falling. It's hard to get server lag with the new router we have, so once I get server lag I can reply back on that.
I've also noticed a little bug where when people playing from a device other than the host ride a horse, the horse takes fall damage from around 3-2 blocks or higher.
I tried reproducing both the horse and player fall damage glitch in LAN in MC 0.15.4 with server lag, and the problem still occured for both. This time though, the horse takes damage like the player does, even if the horse is being ridden, it takes damage as it should, just when the server lags, it adds up all of the falling distance while the server is lagging. So the problem I would say is 33.3% resolved.
Okay, then. I guess I'll just have to get over that feature then or put a suggestion on the subreddit.
MC-108 seems to be for outdated versions of Minecraft, and should it really be working as intended, as in another edition of Minecraft (Windows 10 Edition/Pocket Edition) this event does not occur, it just retracts as usual.
It's from all multiplayer server types: Realms, LAN, External, and Xbox Broadcasting. It's because of occasional server lag for players, and some bug of ridden hores's falling info being sent after dismounting. The horse takes as much fall damage as the total fall height as if it really fell that high, and once the falling info is sent for the player, it sums that up too, but it doesn't send info after an event occurs,
I happened to notice another not-so-big of a deal problem, but it seems that depending on where you mounted the horse from, you are offset. I've only seen this in the current version.