It appears that in UE 4.23, some specific arrays in construction scripts are no longer cleared automatically and retain references to TRASH objects from the previous construction script calls. This breaks some construction scripts which worked in 4.22 and earlier, and also is a regression.
Found in: 4.23.1 CL#9631420
Reproduced in: 4.24 CL#9745507 , 4.25 CL#Main
Link to user's test project:
Result: The array is not cleared with each update
Expected: Array to be cleared before the construction script is called again.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-82611 in the post.