A new hotfix pertaining to Analytics for Learn v 4.2.1 through 4.3.4 was announced in Behind the Blackboard today:
Blackboard is pleased to announce the availability of Hotfix 161 for Analytics for Learn. This hotfix addresses an issue in which activity data load doesn’t stop after reaching the Historical Activity Cutoff Date. This hotfix applies to Analytics for Learn versions 4.2.1 through 4.3.4.
For additional detail, please find the article linked here: Behind the Blackboard