Two external monitors -- displayport breaking every few minutes
After installing f.lux one of my external monitors starts acting up after sundown. Every 200 seconds or so it briefly turns off -- even with gfxCardStatus locking to discrete mode, and even if f.lux is disabled, quit, or uninstalled. I've tried swapping to another color profile, I've tried the terminal fixes, and I've tried uninstalling f.lux and resetting my computer, but as long as it's after sunset my monitors will freak out as if one is briefly unplugged, and the problem only exists after sunset and if a monitor is being used in a thunderbolt/displayport port.
I've got f.lux 36.6 installed and I'm running 10.11.13 on a Retina 15" Mid-2014 with two 1440p Asus PB278s and the laptop clamshell shut. The displayport monitor freaks out almost exactly every 3 minutes and 20 seconds. The behavior continues if the clamshell is open and regardless of whether or not "Automatically adjust brightness" is checked. This behavior only happens when a displayport monitor is being used (even if HDMI is unplugged) and stops if the displayport monitor is unplugged.
I'm not positive, but I believe this behavior doesn't happen when displayport is being used with an HDMI converter and a 1080p display (instead of a 1440p display), but I haven't confirmed that yet.
I believe that adjusting display settings, such as unplugging and plugging things back in, has no effect on the internal 200 second countdown. It will adjust itself to the different monitor settings and then freak out again in 200 second intervals from the last glitch.