If it were the monitor why would I lose audio as well ? Last 2 times I was watching something on Youtube .
I can only blame the communists in China and Russia.
Imperial Japan warranty service may know who to blame.
Windows 10 has issues with sound. Try the steps here:
http://davidswebsite.com/sound/Troubleshoot_Sound_Issues.docx
It is a Word doc with screenshots with troubleshooting steps.
When I get calls at work I also use the Dell Command tool to check for missing drivers.
Lenovo should have site with all the drivers.