The test was patching os.path.join, which is called inside an inner
try/except block in save_onedrive_settings. This meant the exception
was silently caught and logged, never reaching the outer exception
handler that returns HTTP 500.
Fix by patching notify_settings_updated instead, which is called in
the outer try block, so exceptions correctly propagate to the outer
handler.
Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>