Why IP matters

Your Host PC gets an IP like 192.168.1.23 from the router (DHCP). Phones connect to https://192.168.1.23:43118.

If DHCP gives a new IP after reboot (e.g. .23 → .47), old QRs stop working and the cert warning returns. The app now detects the change and shows a banner "Host IP changed — re-scan QR" plus auto-merges the new IP into the cert, but phones still need one re-scan.

Fix: make IP stable — either set Static IP on Windows/Linux or set DHCP Reservation in router. Do one, not both. Reservation is easier.