GT-AX6000 inter VLAN routes

Hello,

I have the above router but battling with inter vlan communication.
I have 4 VLANs
V1: 192.168.0.x (this is the default one)
V2: 192.168.1.x
V3: 192.168.2.x
V4: 192.168.3.x

vlans V1-2-3 have all enabled the allow intranet traffic.
From those 3 Vlans traffic to the Default V1 flows well.
From the default Vlan V1 traffic also flows fine towards those 3.
What I cannot understand is why there is no inter-communication between those 3. eg from V1 to V2 or V3 and the reverse. I cannot seem to find any setting in the router that blocks this traffic.

any help is appreciated

thanks