According to the docs: https://www.jetbrains.com/help/rider/Using_File_Watchers.html#ws_filewatcher_advanced_options
To invoke the File Watcher as soon as any changes are made to the source code, select the Auto-save edited files to trigger the watcher checkbox.
When the checkbox is cleared, the File Watcher starts upon save (File | Save All) or when you move the focus from JetBrains Rider (on frame deactivation).
I absolutely have auto-save edited file to trigger the watcher disabled and trigger on external changes disabled. The program I have set in the file watcher will always run as soon as a type something no matter what.
Is there something I am missing?