If the computer is in VLAN 206, you will need a VLAN interface declared for that somewhere (either on the switch or an upstream router/MX).
If you do have VLAN 206 setup upstream, you might have some VLAN tagging mismatches.
Do you have a topology diagram?
Is the PC getting an IP address when plugged in? And if so, can it ping the default gateway?
Take a look at the example topology in the following doc
https://documentation.meraki.com/MR/Wi-Fi_Basics_and_Best_Practices/Extending_the_LAN_with_a_Wireles...
Also keep in mind that by default, only one VLAN is extended.
Multiple VLANs can be extended on MR firmware 28.1 and above but require Meraki support to enable.