Login issue with WordPress sign ups and Zoho CRM integration token error

Login issue with WordPress sign ups and Zoho CRM integration token error

I have a site that uses the WordPress for log in to WooCommerce and user info and then is supposed to push all info through to Zoho CRM. The site uses Zoho One paid version. However, new users at the moment who try to sign up get the error:

"Error: call to token URL https://accounts.zoho.com.au/oauth/v2/token? failed with status" 

And cannot make an account or log in. 

Any ideas please on how to fix this? Noone can place orders.