HLS Player doesn't use the centralized Proxy Selector.
GeckoHLSPlayer uses the DefaultHttpDataSource to create an Object represents a connection to the remote object referred to by the URL.
And DefaultHttpDataSource doesn't respect proxy values, it uses the URL::openConnection (without Proxy) method provided by the Android SDK instead of the ProxySelector.
To upload designs, you'll need to enable LFS and have admin enable hashed storage. More information