Anyone know what could be causing this ?

Bought this 06 Volkswagen Jetta to flip and after using it as a daily for 2 weeks I just now noticed that it shifts a bit weird when going into fourth gear, what do y’all think could be causing this, the check engine is for an evap leak. When I put the car into the gear selector mode and go into fourth, it doesn’t do the weird shifting, it shifts right on time and smooth.