I have a Play 5 (gen 1) and just bought a Play 5 (gen 2) to be able to use new S2 app.
With Play5 (gen1) I connected sound directly from computer 3.5 mm output via cable to Play5 (gen1) speaker and had no sound sync issues when watching e.g. Netflix/YouTube etc.
Then I installed S2 and connected Play 5 (gen 2) and now I have sync issues, even with direct connection with 3.5 mm cable from Computer to Speaker. I set up S1 again, and unfortunately now also Play 5 (gen 1) has sound delay when playing video (Netflix/Youtube etc).
Any ideas? I know the point of sonos is getting rid of cables….!