I could only get about 45 minutes out of mine before 2.4 radio would stop transmitting. From other posts it seems like if you have another 2.4ghz router close to it this happens. I was using mine as an additional access point until I could work through some issues, and only once I turned off the wireless on the router/AP was I able to use this as an access point.
At the time I didn't know I had a 5ghz device, so I didn't try it, however the 5ghz light always blinks (and the 2.4 would completely stop being on or blinking when it wasn't working).
So far I haven't gotten to 2 days of uptime with it as a router and wireless access point, so time will tell, this is in use in a home office environment and I need to have the stability I used to have (60-90 day uptime, only reason not more is power outtages, changing settings on router, moving around equipment, etc) so I hope it is more than 48 hours.
I also specified a channel, auto was always going with channel 11, which is the lowest power channel, tech support had me pick one in the middle (5 6, or 7), that might have helped if it was an issue with another 2.4ghz router.