I don’t understand - it is working as it should. Modifying button 3 will require a driver. It’s default functions will be dictated by the OS or the application you are running.
Okay, I had to fire up that computer. Opened the Task Manager and ended Logitech Options. Then closed SetPoint within the Notification area and now no middle click on the M705. If I unplug the Logitech Unifying receiver and then plug it back in, the middle button now functions again.
Now using my Logitech K400r keyboard with my HP Pavilion x360-15br that never had any Logitech software installed, the function keys doesn't work without holding down the Fn first. It isn't this laptop alone, it works this way on all computers without SetPoint. Only within SetPoint, can you toggle this and not have to use the Fn key for the F1-F12 keys.
Also interesting, I plugged the Logitech Unifying receiver into the HP that is paired with a M705, K350 keyboard, and also a Logitech Touchpad T650. Remember SetPoint has never been on this machine. And about a minute later, a scrolling window scrolls up from the notification area saying the T650 will work better if I install SetPoint. Now where did that come from? Was it a message sent from the Logitech Unifying receiver?
My only gripe with the G900/903 was premature switch failure. Both are plagued by the infamous double click issue.
This is a super common problem with many of Logitech right and left click devices. Searching on the Internet, there are a few different theories on why this happens. Some say it is a static buildup, others say it is caps not discharging, etc. A temporary fix is to remove the
batteries and clicking on the problem button dozens of times. Or remove the
batteries and let it sit for hours or days. When you install the batteries, it will work fine for hours, days, or months until the next treatment. Funny their dirt cheap mice doesn't suffer from this problem (i.e. M305), just more costly devices.