GL-XE3000: Wireguard server no client

Greetings

My GL-XE3000 runs as wg server and 5G NSA is my main and only network provider (AIS Thailand sim card)

The router shows no client connected.
The handshake on my 2 clients (both samsung device running android) fails:

Handshake did not complete after 5 seconds

Is it a (known?) restriction from the provider ?

Thanks by advance

Hello,

Did the SIM have public IP?

No the IP is private

Sorry but the router that hosts VPN server is required the public IP.

Please communicate with ISP.