I do not know. If I did, I would have fixed it. I note that others have this same problem, and have stated that using other hardware is necessary to view d.tube video content, specifically desktop computers, while I use a laptop exclusively. That is the only clue I have to the mystery of why d.tube quit working for me some many months ago. I have reached out to @heimindanger on Discord - although months ago - to no avail. Any solution would be welcomed by me.

Thanks for asking. It's more than anyone connected to d.tube has done.