Hi @Anz ,
In order to establish a secure connection to the Free or PayG cluster the client must support and use the TLS extension called SNI (Server Name Indication). The TLS-SNI extension adds the hostname information to the ClientHello packet.
To verify, you can use a network analyzer like a Wireshark, capture the ClientHello packet, and confirm whether it is using the Server Name Indication Extension and indicating the hostname. Please refer to the screenshot in the following post in order to see where and what to check: Client is not authorized to connect - #37 by simon_b
I hope it helps.
Kind regards,
Dasha