I don't install native Onedrive client on my devices. Here are the steps.
Install Joplin on mac and enable synchronization and sync via Onedrive. Joplin will create a folder Apps/Joplin on Onedrvie.
Install Joplin on iPad and enable synchronization and logged into Onedrive with the same microsoft account. I thought Joplin will locate Apps/Joplin automatically and synchronize, but it doesn't. It create a new folder Apps 2/Joplin on Onedrive. BTW, the native Onedrive client is not installed on this iPad.
Same problem on the iPhone, only a new folder Apps 2/Joplin is created.