FIXED WITH
- Update IPsec Policies Follow the instructions in this Clavister Knowledge Base article to modify your IPsec policies.
- Modify IKEv2 Settings in the Registry Open the Registry Editor by pressing Win + R, typing regedit, and pressing Enter. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\PolicyAgent\ Right-click PolicyAgent, select New → Key, and name it IKEv2. Inside the IKEv2 key, create a new String Value: Name: SupportedDHGroups Value: 2,14 (This enables support for both DH Group 2 and DH Group 14.)
- Restart the Server