fortifone dot1x issue

hello all , i have this solution in my network (Juniper EX4100 switch connect to Fortifone and pc connected to fortifone) integrated with clearpass.

for PC mac authentication is successfully but for dot1x isnt authenticated , but when i remove the fortifone and connect it to the switch direct it authenticated successfully.

all of fortifones are managed by fortivoice.

this is my product in the network:

#FVE-VM-10
#FON-17
#FON-38
#FON-58

so is there any missing configuration on fortifone?

thanks