I selfhost my Joplin server and use the clients on my Linux desktop, my windows laptop, iphone and Android. It is definitely one of my favorite selfhosted apps. To prevent any issues with sync, the first thing I do when I open the app is to click the Sync button and do the same when I close the app at the end of the day. This way I ensure that I am always working with the latest version. It has not failed me so far, considering I am a very heavy user and have quite a few notes running at any given day.