Gas continues to occupy continuously the whole of the space in which it is placed.
The same thing happens to work when working from home. If your kids have their schedule, you'd better have yours as well (and they're aligned).
Without a conscious decision when and how you work, it can become a mess very quickly.
Well, it sounds like an obvious thing, and you decide to focus on that tomorrow.
Of course, you have A LOT of work today, and spending time on such thing is a waste of time.
I bet in a week, or so you find yourself in the mixed flow of working, taking care of kids, video calls, checking emails without a minute to pause and enjoy life. Ouch.
Think of WFH as a complex project you approach with the team of you. There is a Remote Work Canvas
to help you with that.
When you have an important project at work, I'm sure you get together with a team and plan actions ahead.
WFH requires the same approach, especially when you have kids at home who don't really understand that you're working and not just sitting at the table.
Take some time before work to think about your wfh day and plan it well. It will pay off.