Stance Changing for priests into shadow form isn't working natively like it did in BC. Options are missing from the configuration UI
Manually setting them with Custom Conditionals is working.

Adjusting the following makes it show again and work properly.

ActionBars.lua Line 34

PRIEST = (WoWClassic or WoWWrath) and { shadowform = 7 } or nil,

StateBar.lua line 112

elseif k == "PRIEST" and (WoWBC or WoWWrath) then