Multiple devices

Hello I have 3 devices i use 2 tvs and mobile can you only login in one? When I try to login on all 3 it messes up and stop syncing to them all after day or 2. When I go into account on cinema says login there no account info but when the sync is working there is account info but after while it just says login and stop uploading to account. It does still say sending it to trackit but it not.