I get over 300 mbps speed when I am not connected to VPN. Speed drops to 1 mbps when I connect Cisco Anyconnect. Any suggestion ?
Same issue for me. VPN connection was more like 10-20mbps when I used the exact same VPN connection via Comcast ISP, so I know it's not my company's IT that's throttling the connection.
I spent almost 2 hours with a Verizon tech troubleshooting this, to no avail. We tried connecting to the gateway on a wired connection, wireless, wifi 2.4GHz, wifi 5.0GHz, etc. We adjusted ports and added forwarding. The connection would run at 10mbps for a minute or two for a speedtest, and then taper off to 1mbps every time. Clearly Verizon is the one doing the throttling.
Some googling of old (~10 years ago) Verizon tickets suggests that people used VPN connections to bypass the throttling applied by Verizon when they used jetpacks or hotspots. I'm guessing that Verizon closed that loophole, and now it's getting applied to 5G Home users.
Edit: If it matters, like the OP I'm connecting to a pretty basic Cisco Meraki VPN. VPN type is L2TP/IPsec with PAP protocol.