Nighthawk AC 1900 Dual Modem Router - Low signal/Dropping on 2.4G band

[Slocs]

I've had this router for about a year now. Until last week I only had it connected to 2 cell phones and 2 laptops occasionally. All of which were on the 2.4G band. This week I added 2 apple TVs, 2 fire tablets, and 2 iPads so about 10 total devices connected. Not all are in use at the same time but suddenly the connections would drop across all the devices. I switched most devices over to the 5G band it seemed to solve the problem. However, I'm noticing now that the laptops are starting to lose connections now. We use them for work so Webex and voice calls are dropping.

I have the 800MBPs plan from Xfinity and they confirmed everything is working fine. I just ran a speed test on my iPhoneX and I get about 240MBPs on the 5G band and about 8MBPs (yes 😎 on the 2.4G band.

Before I do a factory reset, I was curious if anyone would recommend another alternative. Hoping to get at least one band working without issue. 

Thanks in advance. 

[plemans]

A couple things. 

1. any device that has 5g and is close enough, put on the 5ghz. its a much faster network. I'd have any streaming/video conferencing device on 5ghz

2. did you try changing wifi channels? 

3. reset it always an option. Maybe something corrupt in the settings.