Horses?Idk what to put here sorry

Sorry for the bad formatting and other stuff, am new here soo heres the bug:

Whenever i play Minecraft and get off my horse to explore stuff,he goes invisible.

It only happens to me when i accidentaly jump into water and it kicks me off.when i look around to find him he's nowhere to be found.The only way to kinda fix the bug is to leave and join your world again