[n66u] Disable radio for 2.4 also disables for 5

[BeyondEvil]

tl;dr: n66u with 380.69 - Disable radio for 2.4 makes 5 disabled as well

Background:
I have a n66u that have been working fine, however I've been seeing some small issues with the wifi on it.

For example: I can be on my phone (iPhone7 iOS 10) and something like Facebook starts chugging with nothing happening. Switch over to 4G and it stops chugging and loads properly. Seemingly I don't loose wifi when it happens and I live in a small apartment so I have full "bars".

This happens both while on 2.4 and 5. Decided to turn off 2.4 (since I have no units using that band). Same issue.

Figured I would give Merlin a whirl.

Steps I took:
1. Reset to factory default
2. Followed the wizard to do initial wireless setup (couldn't skip it...)
3. Flashed Merlin
4. Redid most of my previous settings.

As part of step 4 I disabled radio for 2.4.

Problem:
Tried connecting to the 5 - no dice. At first the SSID was visible, but now even that's gone. If I turn 2.4 back on, 5 starts working. Turn it off, 5 goes as well.

Here's the log:

Jan 21 00:32:34 rc_service: httpd 288:notify_rc set_wltxpower;restart_wireless
Jan 21 00:32:37 kernel: wl_module_init: passivemode set to 0x0
Jan 21 00:32:37 kernel: eth1: Broadcom BCM4331 802.11 Wireless Controller 6.30.163.2002 (r382208)
Jan 21 00:32:38 kernel: eth2: Broadcom BCM4331 802.11 Wireless Controller 6.30.163.2002 (r382208)
Jan 21 00:34:10 rc_service: httpd 288:notify_rc set_wltxpower;restart_wireless
Jan 21 00:34:12 kernel: wl_module_init: passivemode set to 0x0
Jan 21 00:34:13 kernel: eth1: Broadcom BCM4331 802.11 Wireless Controller 6.30.163.2002 (r382208)
Jan 21 00:34:13 kernel: eth2: Broadcom BCM4331 802.11 Wireless Controller 6.30.163.2002 (r382208)