Where is Altius? (Spoiler alert for Shovel Knight Dig)

[CoffreViolet]

Hi.
I've been playing Shovel Knight Dig recently and... well I've been trying to unlock the true ending, but there's a catch:
You see how you need to push Altius into the pit and then you have to find him in Mushroom Mines?
I've done several runs, searched for every nooks and crannies and... surprisingly I always ended up finding him NOWHERE.
So the game's clearly broken, you can't convince me otherwise: Altius is supposed to appear when you begin a "true ending" run, yet the game arbitrarily decided he wouldn't.

Before you ask, I did not pirate the game. I'm saying this because it kind of reminds me of the Gmod Anti Piracy thing that returns a false error to have pirates being banned. I would still be put at ease if it was just a faulty feature like some anti-piracy thing that glitched since it would mean that the game is not broken and there's not some sort of... shovel god who would decide I would not be worthy of getting the good ending.

And I'm putting the reminders here:
I've done several runs. Altius showed up in the first ones but afterwards he did not show up anywhere anymore. And I've searched for every nooks and crannies, so he would have showed up once again by now.
My copy is legal. It has been however offered by a friend through Steam's gift function.
I did search everywhere on Internet to see if that happened before. I found nothing, so I can assume this is the first time this glitch happened.

[CoffreViolet]

Update on the situation: I actually found out that if you're lucky enough, he can show up again.
I still have no ideas on how this happened so I'll just leave this one open just in case.

[OfficialTroof]

you DO look for the secret rooms right...?