If you are using Microsoft teams and can’t see the mouse pointer it is because you were moving the chat window between two monitors. To ensure this doesn’t happen again, don’t move the live chat or live video screen between monitors. It happens to me all the time when I am on a live call and move the person presenting to my other computer monitor. Avoid the temptation is my only advice.
Restarting your computer is the only way to fix this issue. Hope this helps.