When you use Microsoft SQL Server 2016 Reporting Services (SSRS 2016), the Select All check box doesn't work in the My Subscriptions page or the Subscriptions page that's associated with a report.
Cumulative Update information
The issue was first fixed in the following cumulative update of 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. We recommend that you download and install the latest cumulative updates for SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.