Hello @Wolf1000!
Welcome to the Zoom Community! We're glad to have you here.
Zoom only allows you to be signed in to one computer, one tablet, and one phone at a time per account. If you sign in to your Zoom account on a second computer (for example, your MacBook), you’ll be automatically signed out of Zoom on the first computer. However, you can stay signed in on one computer, one mobile device (like your iPhone), and one tablet (like your iPad) at the same time.
This is a security feature and cannot be changed. If you need to use Zoom on multiple computers at the same time, you would need to use separate Zoom accounts for each device.