The current SharePoint connector works fine until you encounter SharePoint lists hosted in MS Groups which appears to use Azure Active directory much different from how the original SharePoint domain works. An easy way to determine this is if your SharePoint lists have a domain with https://groups.companyname.com instead of https://companyname.sharepoint.com.
Currently the work around is having go through the MS Groups API which is complicated and requires extra IT support for access and other credentials.