MDFC's that should enter the battlefield attacking don't.

When attacking with [[Ilharg, the Raze-Boar]] or [[Strefan, Maurer Progenitor]] and selecting a creature card that is also a MDFC, the card does not enter attacking.

This happens even when the other side also happens to be a creature, such as with [[Valentin, Dean of the Vein]].
The card enters tapped, but not attacking.
The card is also not returned to hand at the end of turn, in Ilharg's case and does not gain indestructible in Strefan's case.

Reproduce the interaction using Ilharg, the Raze-Boar or Strefan, Maurer Progenitor with a modal double-faced creature such as Valentin, Dean of the Vein, then trace the attack handling for the selected card. Done means the card enters attacking, is returned to hand by Ilharg's effect, and gains indestructible from Strefan's effect as applicable.

Written by the indexing model from the issue text.