1. Open a new project.
2. I used 138 BPM. Maybe it matters, please do the same.
3. Set the grid to 1/16th
4. Create a new track with an instrument
5. Draw a midi item. One bar length will do. Put a lot of notes in it.
6. Render the midi item to audio
7. On the new track with the audio item, slice the audio item to 1/4th long by clicking on a grid line, slice, clicking on the 4th line on the right and slice again
8. Remove the rest of the audio item. Keep only the 1/4th part of it
9. Glue it
10. Loop it to 289.1. At 138 BPM, this should be about 8:20.
11. Zoom on one of the grid lines at 289.1
You’ll see that the loop marks will be shifted. The audio will be shifted by about 1.9 ms compared to the grid lines (and compared to the beginning of the track)
It doesn’t seem much but considering that in a normal track, anything you would want to loop that long could be a drum, bass, or percussions, it makes the loop feature useless for this purpose. Yet it’s usually how one wants to start creating an EDM track.
I checked it in other DAWs.
In Ableton Live, it will be accurate, although, you can loop the audio only if the warp is turned on.
In Logic Pro X, I think the slice is already buggy. I gave up and wondered how people could use it.
In Cubase, there is the shared copy. I don’t know Cubase well. I think it’s like looping. (The default "loop" will place individual copies but the shared copies behave like a single item, I think). In my test, the audio was not shifted. At 289.1 at maximum zoom, the wave had the same position compared to the grid as it had at 1.1.
In Reaper, if you don’t use the loop but you duplicate or copy-paste it, then it will be correct, except for you will have a thousand copies of the item.
https://imgur.com/a/E5ADfaj