Hello,
I’m french (English is difficult) and write here
[https://framacolibri.org/t/framagenda-davdroid-carnet-dadresse-et-agenda/3344](link url)

If you have ideas…
I see this page :
[https://www.davdroid.com/faq/automatic-synchronization-is-not-run-as-expected/](link url)

In advance thank you