@Koboldo 

You'll need an Omada-controllable switch (ie SG2008) as the router ports are very limited in their VLAN functionality (they are trunk ports...so expect packets to be tagged).  All router ports currently belong to the Native VLAN ID of 1 (a subject of a number of my feature requests to allow additional functionality).

Regardless, please keep in mind that a fully functional TPlink router function requires not just the router, but a managed switch attached.

  @Koboldo @FreeSamples 

Assigning the VLAN to all 4 LAN ports is fine (you can tell he only has a single WAN port configured).

Next, one of those router LAN ports must connect to a managed switch (typically the 2000/3000 series switches, not the 1000 series).  The managed switch port profiles will tag traffic from VLAN 10 on the uplink port to the router, and the router will route it accordingly, either to another subnet, or out to the internet.

Can you describe the path being tested, from client to router?  For instance, I would expect something like:

ER650.LAN2 ->  SG2008P.p8--SG2008P.p2 -> EAP225

I know this works as I do exactly this.  I suspect the issue may be on a non-SDN managed switch, you don't tag VLAN 10 traffic in the upstream, or untag it somwhere.

Lastly please confirm the DHCP setup for the VLAN 10 subnet...ie what are the DNS and default GW settings.