execute command
/summon pig ~ ~ ~ {Tags:["ride"]}
put command in repeating command block
/ride @p mount @e[tag=ride,limit=1]
Dismount pig
Move around
execute command
/data get entity @s Pos
compare pos from f3 and from command
press shift to tp pig
Result
server side - player riding on pig
client side - player can move and do any
Duplicate of MC-259192.