Well I installed freenas 9.10 from scratch on another VM, no issues. I then backed the config and restored. It's happy now. Certainly a bug in there somewhere as it's the same hardware config. Interestingly in my quest I also installed from scratch, restored, and then restored to factory and had the same issue.
Please create a bug report at bugs.freenas.org that includes your system debug (System -> Advanced -> Save Debug) and post the issue number here. Note that the bug will be hidden from others until the dev has a chance to review your debug.