Asus RT-AC87U 5GHz Band Drops; Incessant BOOTP Error Message

[bigprimenumbers]

Hi all,
I'm having a recent issue within the past few days where the 5Ghz band on my router stops working. I checked the router's logs and see this message once 5Ghz drops:

Oct 5 11:04:42 dnsmasq-dhcp[463]: BOOTP(br0) 00:26:86:00:00:00 no address configured

Oct 5 11:04:50 dnsmasq-dhcp[463]: BOOTP(br0) 00:26:86:00:00:00 no address configured

Oct 5 11:04:53 dnsmasq-dhcp[463]: BOOTP(br0) 00:26:86:00:00:00 no address configured

A reboot of the router fixes the issue, but the issue will crop up again within 24 hours.
Checking the Wireless Log tab, 5Ghz shows no values for SSID, Mode, or Channel.

Nothing has changed in my settings recently. The only new device on my network is an iPhone 6S running iOS 9, but things were fine until a few days ago, so I don't think it is the culprit.

The router is an Asus RT-AC87U running the latest Merlin firmware, 378.55 (and has been since mid July).

Any and all help is appreciated! Thank you in advance!

 

[ColinTaylor]

There is already a thread about this here: http://www.snbforums.com/threads/5ghz-goes-down.24165/