Well, FWIW, everything seems OK, for the time being at least. When I had the freezing glitch I was using a 3rd party, USB connected, freebie, company giveaway mouse. Since Christmas I have been using a Microsoft Sculpt Comfort Bluetooth connected mouse and so far no glitch. I will keep you posted on whether this very satisfactory state of affairs continues, or otherwise, at a later date.
BTW I am now running Windows 10 1809 OS Build 17763.195. installed on 15/12/2018. Maybe that's part, if not all, of the solution.