I don't know why, but there are some very strange problems with my system. At times, the right click will stop working on both the mouse and trackpad, only ctrl+click will work.
At the same time when pointing the mouse in the corner, it doesn't respond well. If I move the mouse over an icon in the dock, The dock will freeze, with the app icon stay "magnified". If I move the pointer over the dock, that icon stay larger.
I can click on any other icon, that don't move ( enlarge ) as usual and the app can be open.
I figured the only solution is to reinstall Sierra. (But, wait for it...)
I try to come back with Time Machine...nothing. Disk Utility...nothing. Bitdefender Virus and Malware scan...nothing. I've tried to reinstall the MacOS but after two days the problem appears again.
I've tried to not use some applications in the background, but until now I can't understand if some of that cause the problem.
What can I do to determine and understand if there are some app that is causing the problem or if it's just my settings and data reacting badly with the code and system?