I would second Audio Anchor as an alternative.
I'm surprised Voice isn't working for you. I've been using it without issues. I have a Pixel 5, latest GrapheneOS update and the latest version of Voice (6.1.1 from F-Droid or Github installed).
I'm assuming you have the latest version installed? If so, did you try uninstalling and downgrading to an older version to see if that helps?