Verified in Satellite 6.3 Beta.
1. Set the batch size to 5 in Settings -> Content -> Erratum Install Batch Size
2. Register a host that has at least 6 applicable errata
3. Select at least 6 installable errata (20 for this test) and apply them
Result: The errata were successfully batched into groups of 5
See attached screenshot for verification.
Created attachment 1368188 [details]
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.