What is occurring at the primary level in your cluster/ISD? Maybe those teachers are using techniques and phrases that can build on the beat training they did in those early years.

Dancing and moving to music is essential to developing foot timing. It is not enough to understand how pulse and subdivisions work. Listening to music and the metronome is not enough either. The body must move; counting is not a substitute and foot tapping is only a start. Externalization of the beat in the feet is paramount.

Dalcroze eurhythmics might be helpful for you and your students. Zumba or similar rhythmic calisthenics would be great, especially if you know someone who leads that kind of thing.