One thing to note that progression levels atrophy on their own. I believe it’s typically 2 weeks and they will drop, which also includes the 14th day so if you miss a week in a specific zone, and you move your workout for that zone to the 15th day, you’ll see a progression level decrease because you haven’t worked that zone in that timeframe. It may even be based on time of day, so if you do your workout on day 14 later than you did 14 days ago, the decrease may show up before you get to your workout. This also typically happens when you move from phase to phase and the workout types change and oddly the main culprit might actually be a recovery week since it forces you to skip a week of all intensity zones. Moving workouts around manually will likely cause some issues with plan builder and AT, at least for that week. I believe there are posts around this, but I’m not sure which the best are to link.