This last behavior ir controlled by Linux Kernel drivers. Basically, it says it's paired but...it just doesn't work at all. I had the K780 on the unifying receiver. The Logitech K780 is a more versatile keyboard than the Apple Magic Keyboard. I've tried resetting, unpairing and re-pairing, everything a lay person could think to do, and it is just not working. I tried this with the version of Solaar included in Fedora 23, but I now also double checked this with git master and the behavior is still the same. It was not freely available, but only after logging in on the Logitech support page. (just set it off)For my system (ubuntu 15.10), (a little old, but I can't upgrade because of ATI video driver's issue):After days of manual "setting fn-swap false" in terminal whenever the F1-12 got back to switching keys and media keys, I wrote a little script to automate this job. But that didn't work.Same as I. Comes in handy if you administer multiple machines in your office.It all worked fine on my Windows 10 machine, until I wanted to use the mouse (not the keyboard) with my Mac. It works for my K780 and Ubuntu 15.10. I can hardly find my log for change in syslog. 6. Their wireless range of keyboards and mice are also very top notch and now they come with their proprietary Logitech Unifying technology. It did show it after the first pairing, but it doesn't show it after reboot. However, I see same behavior while using it with Android tablet (officially supported by Logitech). (I have rebooted the system a couple of times (the last time is 5 days ago), mostly because the system can't wake up as expected. So my helper tool indeed wakes up every 3 seconds to check the status. Sometimes I see similar behavior where the very first keystroke (bringing the keyboard back to live) is lost. I have two (one that came with my mouse, a M705, the other came with k780). I couldn’t access the Windows machine anymore either – so how was I going to start the Logitech software to repair this mess?It’s a good idea to mark the receivers so that you know which one is which: in my case, I bought the mouse before Logitech had the big bad Logo Redesign idea, so both my mouse and its receiver have the old Logitech logo, and the keyboard and its receiver have the new logo. Maybe some device IDs?Last night, because of a X window hang, I restarted the display manager (# service lightdm restart), and something magic occurred to my solaar system - Now it will pop up a message at up-right corner, telling me my M585 mouse is back from offline (said "powered on"), and my K780 keyboard as well! I can now unplug the mouse receiver and use it in my Mac, and when I’m done I can plug it back into the Windows machine and use the mouse there. (The Logitech Options for Mac looks using such interval to detect if K780 is back and connected to it. The light on the mouse still came on, but the light on the keyboard (usually comes on when you press CAPS LOCK) was also dead.
I don't know whether others have such problem. The solaar can now respond to the mouse and keyboard's re-connection. Is it supposed to work? This made everything OK again:The trouble was the keyboard was no longer detected on the Windows machine. )For my Mac with their Options app installed, it can keep the Fn-swap off all the time (every time switching the keyboard to it). All of the K780's keys work on all platforms, while the Magic Keyboard is only partially compatible with Windows, and can't be used with Android devices. The Solaar CLI does show it, along with some potentially useful information:I'm having an issue with Solaar and the K780 keyboard due to its power saving. I just now changed over to bluetooth and the problem goes away. Bluetooth keyboard paired but does not work Since to Win 10 upgrade my cheap caseflex Bluetooth keyboard doesn't work. Oddly enough it doesn't show up in the Solaar GUI anymore, which is rather confusing. And while I was waiting for the agent to reply, I tried the following. It seems to turn off after short inactivity, and while it comes back on again as expected when you press a key, unfortunately the first keystroke does not get registered.Logitech customer service said that the keyboard doesn't have memory to keep its setting. Awesome!Here’s a valuable list I haven’t found online, straight from a very nice Logitech chat support agent:Hope this helps anyone who encounters similar issues.With nowhere else to turn, I contacted Logitech Chat Support.