It happened to me again yesterday too. 14.4.3.
Hadn’t happened for a while so I thought I was in the clear - but then noticed a pile of actors in my levels reverting to default state (which is quite drastic as I use various blueprint variables to control visuals)… affected about 400 actors. :-/
To reduce repeated rework, I have chosen to give up on updating them when it occurs and only fix before a public update release… but it just seems to add a huge risk/uncertainty to the release update pipeline - so isn’t a workable solution for much longer.
(Even tried loading variable values from a data table for each actor during runtime to force the darn things into a state - but that proved a major PITA too).
Hope the problem gets sorted.