Yes after power cycle settings do not change. WAN static, LAN DHCP.

But on cpe210 support page I can only find TP_PharOS_1.3.3_160705 firmware. Are you sure that it is not beta?

We want to separate network from main. It should only be used by wireless barcode scanners. My settings works for other brand unit, so I don't think that settings are bad. Maybe broken unit. never...

Yes I can reach web UI after power cycle. To me it looks like DNS problems, but not from main router side.

I did it with wired connection and same happens

Looks like it is dead end. Nothing helps.