@eurilex,

you should downgrade to Omada Controller v3.2.12, that's OC200 firmware v1.2.3. Every lower version is out-of-date and IIRC first 3.2 version was v3.2.4 which followed v3.1.13.

If you did use the new Omada SDN Controller v4.1.5 and you had upgraded the EAPs as required by this new product, you need to downgrade each EAP to last firmware which is compatible with Controller v3.2.12. See the support site for the regional EAP firmwares.

You also should perform a factory reset of each EAP after they have been downgraded. Next, you need to adopt and set up the EAP again. Just create a wireless network on the OC200 and adopt the EAPs, do not change any other defaults for now.

Then test basic functionality: network access, routing, name resolution and if this works you can test Internet access.

Note that the Internet connection of an EAP has nothing to do with Omada Controller and is in no way affected by the Controller.

To provide Internet access your EAP needs an IP address and your router needs to provide DHCP services for the client devices with the correct IP addresses for the gateway (the Internet router) and a DNS server (in most cases the Internet router, too).

If routing does not work, check cables, switch settings (if managed switch), router settings, ping the router, ping an IP on the Internet and check DNS name resolution.

Do not even think about starting a browser to surf the web until all of the mentioned basic connectivity has been tested and appears to work.