When I schedule zoom meetings in my PC, I can see them in both in PC and mobile phone. But when I log in to another device, all the scheduled meetings have disappear. Can anyone help to resolve this please?
You can only be logged in to one of each device type at a time.
When you login to your third device, it is likely logging one of your other devices out - and therefore your meeting schedule will disappear there.
Beyond that, I would double-check you are using the same account/login on all your devices.