I haven't run into this problem on the Mac, but keep running into it on Linux.
I'm using the standard Fedora version of Calibre, which is still 7.11 instead of 7.12, with Qt5NoBlink to disable blinking.
env LD_PRELOAD=/home/[myusername]/Applications/QtNoBlink/qt5noblink.so calibre --detach %U
https://github.com/igogo/qt5noblink
When I open Calibre, the arrow keys allow me to move about the booklist.
If I hit enter at the appropriate column, I can edit it.
If I hit enter again, I end up in the virtual library list. An arrow down opens the menu, and arrow right moves to the search bar.
If I hit enter again again, I'm back to the left-most column and have to arrow back where I was editing the data.
Is there a tweak I've forgotten, or what?