Hi  @IBS 

We also don't know why you need to connect PC back to the network to make the EAP work again. But the problem could be on the Ethernet connection from your Router to the PoE injector.

Please try a short Ethernet cable(within 2m) to connect your main router and the PoE injector LAN port. 

Hi @IBS 

Router, switch (unmanaged) and EAP225-outdoor, that's good enough. 

However may I know the model number of your switch? Are you using the switch PoE port to power on the EAP?

Just in case, could you please try to power on the EAP via it's own PoE injector?

  @IBS 

I suspect the issue may be some kind of ARP timeout on your router, whereby without regular traffic inbound from the AP via the unmanaged switch, your router 'loses' contact with the IP assigned.  Consequently you may be able to 'fix' this by simply doing a DHCP address reservation for the AP on your router (instead of static config on the AP) and set the DHCP lease time to be 15min (anything <30min).  That will cause regular traffic which will keep the ARP table (maps IPs to switch ports effectively) refreshed.  Alternatively, find a way to generate regular traffic from the AP...like and SNMP poll etc etc. so that it stays 'visible' even when no clients are iconnected.

Did you start with a factory defaulted AP, before assigning the static?

Where and how exactly is the PC connected into the network and is it wired or wireless?