Hi EpicRiser
I don't understand, why you haven't the same behavior when using 48000 Hz. It should not make a differrence.
If you hold the note long enough, then i will think you will hear more changes.
I understand, that you don't have any random changes in the attack, when the Sync/ Retrig is set to "Key". To me that's the important thing, so there now is a difference between using the different Sync/ Retrig settings that seem quite logic way now.
What happens after the attack depend on so many things. I think what you exsperience is quite normal.
In example the FM amount, the choosen waveform, the tunings and the Sybc/ Retrig setting have an impact on the end result.
You can ask Arturia support, if you wish.