I'm new in the world of networking.

I have my network like below:

VLAN 50: 10.1.50.x
VLAN 60: 10.1.60.x

I have my Printers and PCs in VLAN 50.

everything works perfectly and every device get an ip address in 10.1.50.x range and the Telephones too.

but the problem is that the Voip Telefons don't rich the Modem (fritzbox).

the ip adress of my fritzbox is 192.168.178.1.

do i have to change the ip-adress of fritzbox or my upstream gateway of my VLAN ?

Thank you,
Best regards