Hello, AndyYan.Set up IMS/VoLTE properly in Treble settings.
This sounds like something crashing hard in the background repeatedly - a logcat would perhaps be useful.
Neither - right now it's a known issue that Moto/Lenovo QCOM S vendor devices have spotty or no SMS reception, and this can easily break daily driving. I've even bought a device just to look into this, but so far I don't know how to solve it within a GSI environment (device-specific ROMs have more room to work with).
Just because this is a generic image doesn't mean there's a generic enough way of flashing it everywhere. I've handled dozens of devices for GSI purposes so far, and many have curious traits that one would never know until a hands-on. You can blame me for being lazy and not summarizing findings on my devices on PHH's wiki, but I won't take blame for not offering an all-encompassing guide that "just works".
I tried to flash the GSI on my device, unfortunately though, it went in a complete bootloop.
I'll be reflashing stock on it, but yeah, that's what happened..
But anyways, thanks for making GSIs so that other people can use them! Its GSIs like these that keep some phones without feature updates or even security updates without much of a choice in custom roms from becoming completely unusable!