Scheduled Refresh Disabled for Smartsheet Data Source

I have a dataset is configured to use Smartsheet as a data source. On PowerBI desktop app, there is no issue adding Smartsheet as the data source, refreshing data, and publishing to service. However, the scheduled refresh online fails. This dataset was initially owned by someone who has since left our org, and taken over by someone else who also left, and now we're trying to have someone take over as the dataset owner again. The scheduled refresh worked after the first takeover, but now it does not work. 

When I click "Edit credentials" another browser window opens to this page, and selecting "Allow" just brings me back to the home page of powerbi service in the new browser window. It does not redirect back to the dataset settings. The data source error is still there and clicking "edit credentials" again shows the same pop-up browser asking for access permissions.

Are we missing something that enables us to connect to Smartsheet as a data source online?

We are on office 365 gcc and logging into Smartsheet via Azure AD SSO by the way.