Still works for me with all the latest updates from Homebrew...
You can enable mpv's log to see what's wrong: SVP's menu -> App. settings -> Add. options -> All settings -> scroll down to "main.setup.player_args" option and set it to "--log-file=~/mpv.log". Or just add "log-file=~/mpv.log" into ~/.config/mpv/mpv.conf file.