So… there came a time when I needed to move from my old 500Gb Home partition to something bigger, and ordered a new 2Tb Seagate, formatted it and split into two smaller (but still larger, if you see what I mean) partitions, the smaller becoming the new Home partition, and… suddenly, the video freeze is gone. Since installing the new drive, there have been No. Freezes. At. All. Seriously.
This means that the “issue” might have been Vivaldi-related, but has been cured – apparently – by the shift to a new drive – away from the Samsung 500Gb to a Seagate 2Tb, and yet I would doubt that it was a simple change of manufacturer lying at the root of all this. Something has happened; was it the access or transfer speed? Whatever it was, it seems to have dissipated, and now my installation of V. is running fine and not stopping the system dead.
If anyone can explain this, they should share it with everyone else. It might be important!