Windows 10 VPN client will not connect to Meraki

[FATeknollogee]

1 - Win 10 vpn client behind OPNsense firewall <--> EdgeRouter 4 (client site) = can connect.

2 - Win 10 vpn client behind OPNsense firewall <--> Meraki MX (client site) = can NOT connect.

3 - Win 10 vpn client behind iPhone hotspot (bypassing OPNsense) <--> Meraki MX (client site) = can connect.

If I do a Site-to-Site on #2, that also connects.

Any ideas why #2 will not connect?