Each KEZAYO account can be in one meeting at a time — in the browser, the desktop app and the mobile app together.
If you open a second meeting while you are still in one, the pre-join screen tells you: "You're in another meeting (…). Joining this one will leave it." When you join, the first meeting ends for you and shows "You joined another meeting". Rejoin it to switch back.
This keeps your audio from playing in two rooms and stops one account from holding two seats. Refreshing the page in the same meeting is not a second meeting — you stay in.