Another inconvenience arose when I inserted a short video in a presentation, which didn’t later work (didn’t even show) in PowerPoint.
I had the same issue. I even tried LibreOffice in Windows, and it still didn’t work.
Searching the web, I just found that it’s indeed issue of Windows. Specifically, with supported video codecs.
But also don’t panic out thinking someone on your network might have been torrenting weird stuff as you may just be behind CG-NAT or have dynamically assigned IP address.
If you do have static public IP, consider the possibility of someone using your wireless connection without permission (even if you changed the password, don’t forget to disable WPS PIN, or at the very least change it from default PIN, it’s easy to forget about).
Why did this not come to my head. My idea was to use video capture card, connect that to another computer or phone, set screens to mirror and then take snapshot of the video.