Password

Hello!

We're running an online school teaching Italian language. We have 3 Zoom accounts for our teachers connected to 3 different mailboxes. Recently Zoom has started requiring verification codes while entering Zoom accounts (it's explained as if a new device was detected, but it's not true). You have only 10 minutes to submit the code, it's made the work of our teachers pretty inconvenient. Instead of starting their classes, teachers had to spend their precious time seeking for verification codes.
Is there anyway to stop Zoom from demanding verification codes? Why aren't logins and passwords not enough?