Is your VPN turned on? If possible, please deactivate it. If your network has a firewall set up, you may need to change the firewall settings to allow access to certain ports and domains. The platform uses Amazon Chime for audio/video calls.
Below is documentation on which ports and IPs are used: https://docs.aws.amazon.com/chime/latest/ag/network-config.html .
Forward this to your technical administrator if necessary.