How to Separate 2x Switches inside same Router (both having Internet Access)

Wondering if anyone can help me out with this...

I want to be able to separate 2x different networks within the same router (as shown in the attached image).

I've tried following a few tutorials that I've found on this forum but I haven't succeeded to have everything working accordingly...

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The reason why I want to have 2 separate networks is because I then want to configure OpenVpn (via a NordVPN server) to only cover all the devices that are connected on 1x of the networks only.

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When I had tried to follow one of the tutorials above for separating the networks, the steps consisted of:
(note: Lan1 settings = "static address" / IPv4: 192.168.11.1 / subnet: 255.255.255.0)

  • making a new Vlan "Vlan3" having the CPU tagged and Port3, Port4 untagged.
  • making a new interface called Lan2
  • set Lan2 as "static address" / IPv4: 192.168.22.1 / subnet: 255.255.255.0
  • firewall rules to basically being nearly identical to Lan1
    (probably missing a few steps in here from what I had followed on that tutorial)

The end results was that I wasn't able to navigate on OpenWrt or on the Internet

So I then played around by trying to set Lan2 to also have a DHCP server and only then I ended up being able (using Lan2 ethernet wired devices) to navigate on OpenWrt, but I still wasn't able to access the internet...

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Would anyone be able to point me towards the right direction on what I need to do to make this work??
Separate 2x Switches inside 1x Router