If you work from home and, like me, hate how quickly Teams will grass on you for not being at your computer / not active, I found the solution.
If you go into your calendar, and at the top, you'll see 'meet now'. If you click that, it puts you in a meeting room on your own but says you're in a call on your status. You can then change your status to available and it will not show you as away for as long as you are in the call. It will stop your computer from going into Lock Screen as well – my work computer is set up so that I can't change the amount of time it takes for it to go to Lock Screen. It saves having to wiggle a mouse around or use a paperweight.
Do with this what you will 🙂 I usually take a nap or do my chores lol