Sync service is giving me a File system operation timed out error on sync of the note I was currently working. After getting this error, several functions of Obsidian stop working such as creating new notes. The app also starts misbehaving, renaming files randomly for example.
I’m just experiencing this again, now sync is hung on connecting to server. I am going to turn off all plugins and themes and troubleshoot.
I did not see a warning of not being able to save, just the warning with the same error as shown in the sync log. Although the console did show the messages others reported on the thread you linked. app.js:1 Sync Error! app.js:1 Timed out.