Mobile data and VoLTE have always worked for me with Android 11 binaries, which are the ones recommended by Jolla. I was actually surprised that SFOS boots and works with SW_binaries_for_Xperia_Android_13_4.19_v2_lena.img, but sadly mobile data did not work with those binaries. So I went back to SW_binaries_for_Xperia_Android_11_4.19_v9a_lena.img.
Regardless of the binaries version, with stock Android 13 I was able to get rid of the echo and color banding issues, so I’m still more than satisfied. Maybe Android 13 based AOSP binaries would bring further improvements, but without functional mobile data using them doesn’t make sense anyway, so I didn’t even bother to further test them.
have to use the Jolla’s suggested ones