Dear Member,

I did not when it happened if I used WinBox in China Mainland connecting Hong Kong MikroTik router, the connection was successful but immediately stop. Even now it is the same.

If I changed the default port from 8291 to another value say 8292, the result was the same.

Now I first use WireGuard from China Mainland to Hong Kong MikroTik router, then WinBox can run smoothly with any problems.

Is WinBox itself any means to solve the problem "China Mainland to Hong Kong" without VPN?

No idea why it did not work the way you tested, but please do not open Winbox to the internet. It is a bad idea anyway. Use Wireguard.

I have the same symptom as you write when I use winbox from behind fortigate with SSL deep inspection enabled