there is also a known bug with vip nt beeing displayedin policy manager when the ipv6 settings are incorrect. FGT and FMG do accept these settings (and do not accept the default Fortinet puts in there when you create a VIP) but the VIP is not displayed in policy manager afterwards.
This can be resolved by clearing out the ip v6 addresses in the vip and save it.
Unfortunately there is no switch to completely disable v6 in a vip :(
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