Vinyl Control not usable because of constant change of tempo

[Russe]

Bug Description

When using Mixxx with vinyl control (Traktor Scratch MK1) there's a constant change of tempo.
For example the track has BPM of 120, then Mixxx will change tempo between range of 119 up to 121. Tempo change is unsteady, for some seconds it will play with 120.5 then for some seconds with 119.7 and so on.
So with this inconstancy it's not usable because you can never play two tracks with same speed.

I tested also with Traktor Pro software and same hardware (controller only, audio device only) but there's no such drift. With Traktor Pro the tempo change is between 120.52 and 120.55

As well I tested different timecode vinyls, but all were Traktor Scratch MK1.

So I guess this is a problem within Mixxx.

Version

2.5.0

OS

Xubuntu 22.04

[Swiftb0y]

What turntable is this? Cheap turntables may also have quite an unsteady tempo (I know my gemini PT 2000 has this issue unless I enable its "pitch quantize" feature). Traktor may be able to compensate better than mixxx.

[Russe]

I'm using Techniks SL-1210 MK2.
When playing normal records absolutely no unsteady tempo can be recognized.