Hey @Neboyarsky sorry for not responding sooner. Might you have clicked the option to Disable for full-screen apps? You can find this and change it in the f.lux pulldown menu under Disable>for full-screen apps.
@XenoXilus Yeah, that's not supposed to happen. I've got a Xeon (Intel) CPU quad core, but it has NO onboard graphics. I'd say just disable your onboard graphics, even though you're probably not using it. Let me know if that helps.
@lorna , I didn't think she wanted to permanently disable f.lux's notifications, but just temporarily while she's eg. watching a movie. That's exactly the kind of thing "Do Not Disturb" is meant for. It has the advantage that all Mac notifications are silenced, not only f.lux's, and also that it will automatically re-enable at the end of the day, in case you forget to turn it back on.
@scapegoat , I meant the Mac's Notification Center, not the f.lux menu or preferences. Do you know how to open your Notification Center? If not, look at the link I posted above. The Do Not Disturb switch is above today's date, so actually you have to scroll up to see it.