I cannot connect to the device portal, I see this error:
The connection for this site is not secure10.110.8.181 sent an invalid response. Try running network diagnostics with Get Help. ERR_SSL_PROTOCOL_ERROR
I can build and run programs with visual studio, but I cannot acces the device portal
I allowed the browser to access Hololens 2's IP.
About how to connect to the device portal, you can access https://<YOUR_HOLOLENS_IP_ADDRESS> via a web browser on your PC. Please refer to this tutorial for details Using the Windows Device Portal - Mixed Reality | Microsoft Learn.