Symptoms
When you use Microsoft SQL Server 2016, you may experience high PAGEIOLATCH_SH waits that's caused by heap scan. This issue doesn't occur when the MAXDOP setting is set to 1.
Resolution
This problem was fixed in the following cumulative update for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.