Sync between desktop and phone

[JackGruber]

As I am not familiar with dropbox sync, I can say little about it.
Has the App or Joplin folder been renamed in Dropbox?

Error: POST files/list_folder: Error (409)

Update: I have excluded, some time ago, the synchronization of .lock, .sync, locks and temp in Dropbox/Applications/Joplin. (With the Dropbox application itself, not possible on the Web, AFAIK.) I restored .lock and .sync, but I still had the same error. I restored the two others, and synchronization went without error. I fear the advice given above is no longer valid, and we have to live with permanent creation and deletion of files there. I disabled the notifications of Dropbox to avoid se…