Snap and quantize are for cue, loops (in/out) and efx respectively. Sync is what is getting muckered up when you get to sub beat loop lengths. I had the same issue when droppiung down from 1 to 1/2 beat loop lengths–thought that Traktor was supposed to turn sync off automatically but since your incoming track is not master then IDK…
I’ve seen master jump back to the track that’s ben playing the longest. So disable sync on the track your bringing in at the same time you hit it to go to 1/2 and you should be good.
Sync wont stay on and Loops will break sync if the are not gridded.
Non integer loops smaller that 1/2 beat can also break sync and will do if there is not grid.
As a personal rule of thumb, I keep my sync button mapped as a trigger and not a toggle. Decks in Traktor generally do a good job of staying in time after being beatmatched just once. I’ve never seen a need to have them constantly locked in sync every second of playback, except under certain performance conditions. It brought in issues with effects, loops, and like your case, loop rolls.
Point is, you don’t have to muck around with master deck settings, just unsync the deck. The tracks will stay together, I promise. Try it out.
Quantise and Snap are great but for placing and using cue points you’re sometimes better off without. If you want to do anything quick with them those functions limit what’s possible.
snap and quantize are based on the grids. If your grid is off or if you need to start a loop on certain words that are in between grids. Or sometimes grids are off and you need to start a song on a down beat.
i map to a toggle. when i load the next track and i know im speeding / slowing the next track, i hit it once to sync, then toggle it back off so i can cue point juggle quicker.
edit: derp. in typing that out, i realize the err of my ways. thank you again, djtt