This error has occurred with both a Samsung S7 FE tablet and a S22 phone, and only half happens with a S22 Ultra.
When accessing notes that are being shared the system will drop out of being in dark mode, though dark mode will still be toggled. We then have to toggle dark mode off and on to re-enable the settings applying to the system.
Both accounts linked to the shared notes run their devices in dark mode full time.
