I have Winwows 10 updated to date and I bought a license of Avast Premiun Security installed on one of my HD, this one does not work.
In the other HD with Windows 10, I only have the security of windows 10, in this HD I can connect a USB to the Samsung S7 phone without problem.
Also in Notebooks (Win10) without Avast, you can connect the phone with USB without problem.
So I think the problem is Avast Premium Security
tks