In my time managing a team of about a dozen WFH employees, I had 10 of the 12 overworking every damn week. They were putting in time off-the-clock just because they were sitting at their desk without anyone coming in to shut off the lights and because they were comfortable at home. In the four years or so that I did that job, I had more problems with people overworking themselves than slacking off.

There were a couple times employees were obviously doing the bare minimum and playing video games. Since I managed in-person teams as well in the past, I know that this is normal, there will always be some percentage of employees that cannot stand working and try to do anything to avoid it. This happens WFH as well as in offices, but when it's WFH the company managers and owners don't have visibility on it, and thus feel not in control, and that's the very worst feeling for most of these folks who run companies.