When did this specific change happen to annotations?

[Zeke Williams]

Some of you may already be aware of a bug that causes deleted
annotations to remain in the document even after being deleted.
Checking it out today, it still contains the annotation entry, but the
contents is a bunch of garbely goop combination of letters and
numbers, previously it would show it in plain text plain english. Did
something get changed in recent months for this to happen?