[pacman67]

I think the fact your gearbox was shifting badly to start with May point to it having an issue then. What was the fluid like before you changed it ? What mileage has the car done, was it used for towing, or short trips like a taxi. If you look at volvo service data it does suggest that these boxes are not necessarily sealed for life and can be subject to fluid services. The other point is there is a software reset recommended following a fluid change to prevent fault messages from occurring afterwards. I'd get it hooked up to a Vida system and see what codes are up.