OA4 gearbox

Hi all,

I have a skoda octavia 1.6tdi from 2016 with 35000 miles on it.

At 18000 miles the clutch was replaced under warranty because of the gear getting stuck in reverse and i had to put a good amount of force on it to get it back in neutral.

Since the clutch has been replaced, i have the feeling that the gearbox doesn't change gears smoothly anymore.

It's the worst when i change gear from 2nd to 3rd gear. It feels like when putting it in 3rd there is this metal edge where i have to push by before it clicks in 3rd gear. The feeling is worse with a cold engine and even much worse with temperatures below 8 degrees celsius.

My car drives very smooth, but because everytime i have this 'edgy feeling' when changing gear from 2nd to 3rd, it ruins the driving experience.

Sometimes when its cold en i change from 1st to 2nd i also get i very little noticable cracking feeling , like when you dont clutch well and you crack the gearbox or like when you would put the gearbox in reverse before you stand completely still (i never do this to be clear but its the same feeling/sound).

Doe anybody know what this could be?

The mechanic of skoda says nothing is wrong with the gearbox, but that same person told me when they changed the clutch that the synchromesh of the gearbox where fine, while i found out later that they didnt even open the gearbox so i dont completely trust this mechanic.

Can changing the oil of the gearbox help with this problem? Or any other suggestions?