From the 1.5.23 update:
Some tanks lose access to Armor Piercing abilities.
Tanks are supposed to be excellent against fast creatures, let’s keep these creature’s focus in that direction.
I miss the days I didn’t have to deal with a tank breaking my shield… But seriously, if we’re ignoring this statement now, can Stegodeus at least have it back? APR isn’t even as bad as DSR anyway.