Tado setup - Reauth

Hi guys,

Sorry if this has been asked before. I installed HA a couple of days ago so am very new and learning a lot, very quickly. I have added the Tado device to pick up my smart thermostat however I am constantly being prompted to re-authenticate. I click the link, log in on the Tado site, all looks good until it comes back to HA and then it says it failed. Am I doing something fundamentally wrong?

Thanks