Hello Alex,
- Have you tried to sync it using the 'Sync All Networks' button in the UI?
It's located under 'Hosts' main tab > select the host > 'Network Interfaces' sub tab > 'Sync All Networks' button.
- Can you please go to the 'Setup Host Networks' dialog(located under the same path^^) and hoover on top of ovirtmgmt network? a tooltip should pop-up and it should let you know what is the reason that the network is being out-of-sync. Engine probably complaining about a difference between the configuration on the host and the DC.
- How did you end up with this situation? what happened before the network become out-of-sync? did it happened after the hosted-engine deploy was done?