Buffer length is affecting grid placements of recorded audio stems?

[Teedoblee]

Hi, I've been having this problem with audio stems falling off grid after recording vocals, guitars etc. even my metronome.
Ive been using a normal MOTU M2 interface and a buffer length of 128 smp for the longest time without any problems. The problem appeared to me when using a Apollo Twin X Duo in an another studio.

I've always heard that you could run higher or perhaps the highest buffer lengths without delays when recording with an UAD interface and that is indeed true, while tracking with one of my friends we went trough a couple off takes and then at playback we noticed that the audio stems were off grid by a significant amount..
This was pretty weird, and I had to manually nudge the audio clips to get them on beat again. Again, like I said while tracking we had no problems with delays even with a bunch og plugins running in the UAD Console.

Ive been trying to troubleshoot this problems for a couple days with no success. Driver software dose not seem to be the issue after multiple attempts at reinstalling both UAD software and FL Studio.
I had also tried to disable/enable various PDC and IDC settings but this dosent seem to be affecting anything really.

The only solution seems to be using low buffer lengths like 128 smp or lower and even with that I'm still not perfectly on grid.

I have read a couple of treads of other people having the same issue here on IL forums but no one seems to have found a solution and rather deemed the problem a consistent one. I was hoping that using such a renowned interface like an Apollo would be great with high buffer lengths, especially on bigger projects with a lot og tracks and plugins, but this problem seems to persist.

Im going to include a attachment that shows my metronome being played from headphones, trough mic and into playlist at different buffer lengths, there you ca see how much the audio stems are off grid.
Metronome tracked at 128 smp, 512 smp and 1024 smp buffer lenghts.

NOTE: **UAD APOLLO HAS DIRECT TRACKING TROUGH INTERFACE (IT`S PRETTY MUCH REALTIME TRACKING). THE PROBLEM LOOKS TO BE WITH THE BUFFER LENGHTS IN FL STUDIO AFFECTING GRID PLACEMENT**

[D3Mens]

Interesting, Did you measure how many samples ...