I used 4.7.2. I replicated bug in this video:
project used was a 4.7.2 project and not upgraded from another version. Relatively clean/blank.
It seems to work for constructor (this time, not sure what I did different last time). But it still bugs for EventBeginPlay as you can see in video.
Note that adding a print-string to child BP, will totally cancel out parent-EventBeginPlay code (as expected). This is obviously not intended behavior.
File > Refresh All Nodes does not fix problem. Restarting also does not fix problem. Copy-pasting from another, newer BP is currently only way to fix it.