Based on the backup history on my USB drive where the last backup that I can read was on the 4th March this year, I would consider it likely that it was the release on the 27th March that is the likely culprit:
If not that release, it may have been the next release:
Which of the two was the cause would depend upon the date that I applied the updates which could easily have been delayed a couple of weeks at that time since I was rarely in the house.