print-playing-formats %aa and %aA report wrong value
The bug has been initial reported on https://bugs.launchpad.net/ubuntu/+source/rhythmbox/+bug/1788005
"These formats incorrectly supply the value of the track artist, instead of the album artist.
To fix this in 3.4.2 (Ubuntu 18.04), edit remote/dbus/rb-client.c lines 301 and 308 to say "xesam:albumArtist" instead of "xesam:artist"."