Lag when move from one chunk to another.

If I stand at co-ords -49,62,309 game works perfectly, If i stand at -48 (or less) game lags terribly and minecarts continuously stopp running ec. If i stand at -49 i can see the minecarts running through affected chunk(s) with no issues. It seems my charatcer is causing the issues. This is also relelvant if I leave the affected chunk(s) in any direction. Seem to only happen in the Overwold. Not seen any isseues in the Nether or End.