Nether portal glitch

So, hello again. Just fix the nether portal glitch please: when I go into a portal, sometimes I Spawn random without portal and my X or Y coördinates are 2k-5k above our centre. It only happend in survival but in multy and single player. It happend 7 times now, 5 times going to the nether and 2 times going to the overworld. It only happend to me and never to my friends(maybe cuz I'm the owner of our survival world?).