If you're using systemd-resolve either on your own system or on the Pi, single-label DNS lookups won't be propagated. (You can see that you're using this if you

If you're using systemd-resolve either on your own system or on the Pi, single-label DNS lookups won't be propagated. (You can see that you're using this if your upstream resolver is set to 127.0.0.53 anywhere.)