Primary weapon reloads the last shell of ammo storage when ammo stowage get destroyed

I was playing Leopard 2A7HU and I always carry 16 shells, including 15 DM53 APFSDS shells and 1 DM11 HE-TF shell.
In the battle, I already have a APFSDS shell loaded. However, when someone managed to destroy my first-stage ammo stowage, my loader began to reload the main gun with my last shell, a DM11 HE-TF shell.
I wonder whether this is a bug of this tank or it’s just a normal phenomenon (maybe its some change I haven’t noticed?).
You can check the replay here: Gaijin Entertainment - Single Sign On
And here are some key points:
1:42: I had loaded a DM53 shell.

1:57: Someone managed to destroyed my ammo stowage, and my loader began to reload the DM11 HE-TF shell. (In the replay, it suddenly reloaded the HE shell, while in the battle, it took 6 secs to reload)

3:28: I fired the last shell. According to the explosion, I believe it’s HE shell rather than a APFSDS shell.