• Fix Huawei HiLink SMS in debug mode: inbox, sent messages, counts, sending and deletion keep using the web API while AT ports remain available for metrics and USSD.
• Honor explicit HiLink/IP SMS port selections with an active AT metrics port. Fix saving valid HiLink/IP SMS ports without requiring a reboot.
• Add an independent USSD sending port in the USSD settings panel. The choice is saved per modem, survives automatic SMS port setup, and is used only if the serial device still belongs to that modem. Clear the field to restore automatic selection.
• Offline regression and Huawei API tests pass. Confirmation on the affected E5573 hardware is still needed.