Sync issues w stereo loops when quantize / threshold is set

[rafrombrc]

Hi there!

I've finally figured out how to reliably reproduce this very strange issue I've been having with SooperLooper. Here's how:

1. Create new SooperLooper session (I use slgui)
2. Add a stereo loop
3. Set quantize to either cycle or loop
4. Set threshold to any value greater than -inf
5. Hit record
6. Record the loop
7. Hit record again

After I do this, the first time through the loop will only play on the left channel, second time through both left and right, and then on successive loops it alternates back and forth: left only, stereo, left only, stereo, etc. Even worse, though, is that after a few cycles the left and right get out of sync, so in the cycles when they both play they're offset by about half a second.

I'm running on Linux, and have had this happen on Ubuntu Studio 20.04 and 22.04, and using SooperLooper versions 1.7.4 and 1.7.8. Notice that all of the steps listed above are required. If quantize is off or set to 1/8th, no problems. No threshold set, no problem. End the initial record by hitting trigger instead of record, no problem. But with those steps it'll happen every single time. And apparently at least one other person has hit this issue, as well.

I hope this is useful, and I hope it'll get fixed. Regardless, thanks so much for SooperLooper... it's been a wonderful creative tool for me!