My problem with very low doorbell 2 speaker volume and terrible voice quality from the doorbell speaker went away a few weeks ago. Apparently due to software version updates of the app and/or doorbell.
Prior to this I was working around the problem by not enabling time line. Now the option to not enable time line is gone and it’s on all of the time.
My Samsung phone is on android v9, the app is v3.20.0, and the version of the doorbell 2 firmware version is “up to date.” (It’s interesting that ring hides the firmware version number and doesn’t publish release notes for the firmware updates.)
So maybe there is hope for anyone still having the ptoblem.