Weird experience please help!


New member
Jan 1, 2022
So I have a 2015 Golf SV 2.0 Tdi which had a coolant leak,
Took it into garage and was told it’s the water pump, whilst doing the pump the garage did the timing belt also,
Got car back week ago and all was good,
But now noticed that once accelerating from 55mph + the car barely accelerates but the the RPM increases,
But accelerating in lower speeds and gears there isn’t any issue!
Feels laggy?
Anyone have any ideas of the issue? Is it timing belt related?
Thanks in advance