Installed debian with gnome shell (3.20.2). Added a couple themes but they don't look right at all when I switch to them. Any theme except Adwaita appears show the window border ok, but the internal controls seem to fall back to some default style.
I ran into this before and can't for the life of me remember what I did to resolve it (maybe a missing package or some env setting...).
- installed gtk2-engines-murrine
- user themes extension is enabled
still no go :(