Hard to tell the exact reason for a deer's pattern change. It could be food source, your hunting pressure, others hunting pressure (you did say public land). The weather, the rut, there are too many variables. The one thing to do is pattern them from year to year. It may not help at this moment but will in the future.

As the deer passed you, where were they going? Are they still arriving there?

Good luck, there may be a reason or pattern. Just keep searching.