Whats up with the HE? 53rd thread about "fixed" issue, year later

I have started playing quite a bit after Mutsu was released and I have noticed that something has changed in the game. Something that we had here maybe 2-3 years ago, where HE shell with some armor pen, you pen anything and the shrapnell just pass through any armour. I think I had here post about the same thing 3 years ago.
I am mostly playing battleships and about half of my deaths is to 4,5,6 inch HE or HE-VT. Not only these guns can finish off battleships, but in some cases like the US the HE on battleships does very little damage, with long reload. The small guns with fast reload are completely shredding battleships.
I am 100% confident that USS Brooklyn with just HE can finish any battleship, thats concerning a bit, but it can do it faster than Arizona with HE or any other battleship actually.

Since the update, there is a bug that when you hit a ship below the waterline with HE ammo it can ignore the armor.
It doesn’t do it all the time and I don’t know if any other condition has to be fulfilled.