The 10 III echo issue is that during normal calls (via earpiece, not speakerphone) the other party (the person you’re talking to, not you!) hears echo, the stronger the higher volume level you have.
See @flypig’s post from May '22 when Jolla introduced support for the 10 III. It describes some of the issues, including the echo cancellation problem:
With Android 13 it seems to be gone, at least no one I called in the last 4-5 days reported hearing any echo, even though I have call volume set at the max level.