I exactly have the same problem.

Sadly that program doesn't suit my needs and so does f.lux if it can't completely ignore my second monitor. :(

Thanks @Paul-Harris - for some context, f.lux v4 avoids constantly looking for color changes and tries only to "fix" what other programs do in a few specific ways, so you're seeing what's expected, except that f.lux should definitely be detecting any new screen that makes your desktop bigger, so that's a bug.

That list currently includes: plugging in a new device (which seems like it's not working here), returning from sleep, and switching apps (like alt-tab).

When you plugin a device, does it look right for a bit and then reset later? Or does the tint instantly disappear?

Thanks for this, i wouldn't expect this to be the case either, the software is only installed on 3 machines. Mine (never rebooted) and two others that are rebooted perhaps twice per day maybe 3 at most!
I will have a look and see if anything comes up. It certainly didn't seem right to me, maybe it is a bug on sophos!

@TwoCables
Thanks. This worked great.

Until Microsoft announces that they're dropping support for 32-bit programs, f.lux will remain 32-bit in Windows. After all, what sense would it make to create a 64-bit version of a teeny tiny little program like this when there's no need to do it?

@TwoCables Well, pray tell how to find useful info? Tnx

Can you fix your screenshot?

Try uninstalling it and re-installing it and then restarting the computer.

Also, I think you have to make sure Windows Night Light isn't enabled.

You're welcome. Lorna and Michael (the wonderful people who are behind f.lux) have taught me during my time on this forum that the brightness level is almost as important as how much blue light is in the light source - at least as it pertains to how 'alerting' it is for the body. Of course, it's also easier on the eyes when you've been awake all day and are getting tired. We get very sensitive to light after being awake for ~14 hours.

You might also be able to reduce the amount of blue light your monitor emits by adjusting its colors using its built-in menu system.

@fetymann Huh, I tried disabling Flux for the individual programs/games but that setting doesn't actually affect the dimming (just the colour temp stuff) and as a result I never thought about trying the "For Fullscreen Apps" as I thought it wouldn't either. I can confirm setting "For Fullscreen Apps" will disable both colour temperature and dimming and works for my purpose.

Although that setting desperately needs a blacklist/whitelist as well, I don't want fullscreening a youtube video at night to blast it at full blue brightness at my face.

@herf were you able to reproduce the issue? if you weren't, I can try and reproduce it in a VM for you.