IKEv2 VPN not working after updating to MacOS Catalina - User authentication failed with username authentication settings I had a IKEv2 VPN connection configured with MacOS Mojave that worked perfectly.

After updating to Catalina I can't connect to the VPN with the message User authentication failed.

Any idea how to fix or troubleshoot this problem?

The only logs I've found are in /var/system/wifi.log:

Wed Oct  9 23:47:06.462 &lt;airportd[300]&gt; _processIPv4Changes: ARP/NDP offloads disabled, not programming the offload
I had the same problem and I fixed with changing "Authentication Settings" from "Certificate" to "None". 
After this change, you will see 2 new options appeared just below, "Shared Secret" and "Certificate". Select "Certificate" option and reselect the certificate that is already used for the VPN connection before. 
Then click Connect button, confirm applying changes and viola!