I have TP-Link TL-WR841N router with approx 8 devices connected regularly. Recently I've been noticing that the router isolates connected devices from each other despite the checkbox of "Client Isolation" being unchecked. Just to verify, I enabled and disabled Client Isolation and the problem seemed cured. But, after an hour, devices again couldn't ping each other. What could be causing the issue?
Some points which I think might be helpful:
1) I'd hard reset the router less than a week ago. The only modification I've done since then is setting up a few DHCP reservations.
2) My ISP provides internet through Static IP mode.