You can work around this issue by explicitly telling Anki what the GTK theme is. Run the following commands in a terminal:

theme=$(gsettings get org.gnome.desktop.interface gtk-theme)
echo "gtk-theme-name=$theme" >> ~/.gtkrc-2.0
echo "export GTK2_RC_FILES=$HOME/.gtkrc-2.0" >> ~/.profile

Then log out and log back into your computer, and Anki should pick up the GTK theme.

https://forums.ankiweb.net/t/anki-doesnt-start-under-wayland-linux/10409

A solução acima não funcionou!

A única solução que deu certo, foi intalar uma versão mais antiga e instalando pelo o snap: https://snapcraft.io/install/anki-woodrow/ubuntu