So you could be facing an issue where Avaza Account is showing the integration to be 'not connected' to Xero, but on Xero's end, the integration seems to be connected (in the Connected Apps).
What can you do on your end?
Disconnect from Xero's end and re-attempt the Connect to Xero from Avaza.
Check if the pop-up shows that the relevant Account is available to be connected.
Select the account and try to connect.
If the Integration page is still showing the integration as not connected to Xero. Please contact our Support team and we shall investigate it further for you.
We have a known issue where users are unable to connect to Xero while using the Safari browser on Mac OS. We suggest switching to Chrome or Firefox browser when configuring your Xero integration.