Firewalla Purple - VLAN - Segmentation

Hello,

I have setup a Firewalla Purple successfully in my home Environment wit the below setup:

ISP (Hub in Modem mode) <--> Firewall Purple <--> TP-Link Managed switch (TL-SG108E) <--> TP-Link Deco x60 (AX5400)

Deco X60:

is setup as "Operation mode" 'Access point'

Firewalla Purple:

I have setup 2 VLAN's;

VLAN20

VLAN30

TP-Link Managed switch (TL-SG108E):

I have setup the VLAN's on the TP-Link

VLAN > 802.1Q VLAN > Port 1 tagged (Goes to Firewalla Purple LAN port) and Port 7 untagged (where I want the VLAN on the switch for work)

I changed the IP and subnet entirely yet I am still able to ping the gateway on the main network from the VLAN network.

Any ideas as to how I can stop communication of VLAN to main network?

Thanks