Issues with seeing devices on the network

I've setup a new EdgeRouter Pro. I have Eth2 as the LAN plugged into our switch. Eth3/Eth4 are Ubiquity APs. Everything can get on the internet fine, but nothing can see internal traffic - i.e. the server or the printers. I'm wondering what setting we need in order to have the local traffic be able to see each other.

We are running EdgeMax OS POEv.1.8.0.

Any help would be appreciated.

Thanks,

Melinda