So, programs that use Client Side Decorations (damn you, GNOME!) do not play nicely with dtwm. You can't move or resize such programs. Now there is a way to get around this with GTK-NoCSD for anything that uses GTK3 or GTK4, but it does not seem to do anything with programs that don't use the GTKs. Namely, the Discord client, which is an Electron app. So unless there is a way to force Discord to disable Client Side Decorations, we should look into allowing dtwm to better handle such programs... maybe peek at how KWin does it? They have (had?) an X11 version that supports it...