An array of a structure that has been modified without the array's blueprint being complied results in the values of the array element being reset. Compiling each blueprint that has the array of structures fixes the problem.
Tested in //UE4/Release-4.25 @ CL 14469661 and this occurs as well, so not marking as a Regression
The values in the array of structures have been reset
The values for the array maintain their values
There's no existing public thread on this issue, so head over to AnswerHub just mention UE-112718 in the post.