Wifi gets disconnected when connecting to VPN via Cisco AnyConnect Client

I have a Macbook Pro 2017 model. Whenever I try to connect to VPN via Cisco AnyConnect Client, my wifi gets disconnected. I have to again restart my router and try with the Cisco client again. In 2-3 attempts I do get connected to the VPN. But till I get connected, I have to retry the steps and manually restart my router. How I can resolve this issue?

I had several clients that this problem. Cisco AnyConnect can fail to connect if your router is misconfigured. The only way this was cured was by contacting the Internet Service Provider and having them reconfigure the router from their end to enable VPN connections to succeed.