I struggled with the same problem and tried all the various options for Debian 11 Bullseye lxde-core.
I now use package cmst and connman with lxde-core on Debian 11 Bullseye and it has been working great, even more stable with certain wifi chipsets than using wicd on Debian 10 Buster. The following brings everything required for Debian 11 Bullseye lxde-core: apt install cmst -y
