Unable to create new sync to crm

Unable to create new sync to crm

Hi, I'm trying to add a new sync to CRM in Campaigns.

When I click on 'new sync' > 'immediate' & select 'contacts', I get a message 'Unable to connect to Zoho CRM.'

I already have 2 syncs which are working so it SEEMS connected. And in the integration dashboard, the CRM tile has a green dot saying 'connected', so I don't know what else to do.

Please help!