Hi…,
It is important you have the latest Zibo version.
There was an issue with the Zibo 737-800X, where the FMC showed NAV DATA OUT OF DATE, even though it had been updated. Please see FMS data not working for ZIBO mod 737 - #4 by Tony31841 . An updated version was issued by Zibo to fix it.
See also Navigraph didn’t update the Zibo 738? - ZIBO B738-800 modified - X-Plane.Org Forum
If still an issue, please see para 3 of FAQ - Nav Data Out Of Date
Cheers
Ian