AES 256 PFS
The session will establish (green lights) but traffic will not pass if configured using IPSec authentication algorithm:
SHA256
SHA384
SHA512
SHA1 / MD5 work OK and allow traffic to pass.
IKE authentication using SHA256/384/512 does not appear to cause an issue.
Fails on 7.504<>7.900
Not an issue on 7.504<>7.504
Not tried on any other IPSec Policies yet.