hello the piwik pro team,
i’m facing the same issue
Community Connector Error
There was an error caused by the community connector. Please report the issue to the provider of this community connector if this issue persists.
Connector details
There was an error while authenticating with the Piwik PRO API. Check your credentials and try again.
and using the latest version
if you have any idea about how to fix it, would be glad to hear 
thanks & have a lovely day
kind regards,
sébastien