Hello
@WXC,
Many thanks. I am aware of how to set it up on Android.
About the "thewindowsclub" article, I have read it before. The Registry trick implements a proxy domain setting to all UWP apps. The GPEdit method needs a proxy domain and a restart! I use a PAC file and the toggle key in settings to on/off it (SS above).
There is a difference between Telegram Desktop and Android (mobile version). On Telegram mobile you can open Telegram (without VPN/Proxy), see the channels (MTProto proxy channel and proxies) and select a new proxy if the current one doesn't work. On Telegram Desktop you can't open the app without a VPN/Proxy and see the channels (to set a new MTProto proxy)!
On PC I can use Nekoray to force UWP apps to use proxy settings as a VPN, I don't use Nekoray, and I don't want to use it (or any 3rd-party app) for proxy settings.
I don't know who had such an idiot idea to separate the UWP and Win32 apps' proxy settings.