BrowserStack uses custom VPNs on the remote devices to connect to the internet. Also, we have a cascading Proxy configuration within our infrastructure to support our implementation and testing on BrowserStack.
The VPN or proxy is enabled on all BrowserStack devices and cannot be disabled due to our implementation.
If your application under test is detecting this VPN or proxy on our remote device, then the only workaround would be to disable this check for the application under test with the help of your app development team to proceed with testing on BrowserStack.