Hi John,
This issue was resolved in Build 6948 (Jan 9, 2019):
Fixed: "Block Senders" action not moving email to Junk Email or Deleted Items folder.
I had come across the issue as well, and it's no longer occurring in Build 6956 (Jan 17, 2019).
Andrea Free
SmarterTools Inc.
877-357-6278
www.smartertools.com