Hello, Proton VPN team:
Presently, if the primary ProtonVPN API endpoint is inaccessible due to blocking, the application attempts to connect through alternative available endpoints.
However, upon examining the backup endpoint, a critical issue emerges: it solely utilizes port 443 for HTTPS connections and lacks additional ports.
Consequently, in restricted environments, users may encounter difficulties in establishing a successful connection to the API server, significantly impairing the functionality of the application.
To address this concern, it's imperative to include a non-standard HTTPS port for the backup endpoint.

Thanks.