JJL1990 The connection itself is working fine (albeit with constraints, see below) via both downloading the PowerBI desktop client or installing from Microsoft store. Is your security issue in PowerBI desktop or after you publish to PowerBI service with refreshes not working. I have noticed in the past few weeks (May release), the credentials in service are no longer working in some cases. I can usually re-authenticate in service and then refreshes work again. However, in one case (not QBO related) I ended up having to delete the dataset from Service and republish and then it was fine. Ugh. I love Power BI, but there do seem to be niggling ongoing problems with Service.
As for QBO itself, the biggest problem I have with the connector is you can only connect to ONE company within a QBO account within a report. This is highly frustrating because we have 4 companies in our QBO account. I've worked with Support on this and they say that the Product team is considering this. As an alternative I tried to stage the data upstream in Azure Data Factory ADF). That was no go because QBO require OAuth2 and ADF currently supports OAuth.