Got to the crate pushing area, tried every button, but Miriam can't push the crate ):
I tried reloading from the last save - no good.
EDIT 1.1: The way I "defeated" the crate was slow, but it did work: slide 2-3 times to the left side of the crate and push right without pausing - the crate budges tiny bit to the right, repeat till you are able to jump from the crate to the chest level (it took me 5 minutes of pushing).
EDIT 1.2: Another way worked for me: changed the graphic settings in the configuration to 'full screen' + '1600 x 900' (or '1280 x 780') and didn't encounter this bug at all; the crate moved normally (and overall performance improved a little). Try changing the graphic settings to lower resolution - it may help (it solved the issue for a few people).
EDIT2: I'm attaching a save file (saved after the crate box area). Place it in the following directory:
C:\Users\ [username] \AppData\Local\BloodstainedRotN\Saved\SaveGames .
EDIT 3: Theory: I believe this bug is tied to the PC/laptop performance overall; slow pc/not good performance = crate boss bug. Confirmed by a few people I heard it from.
So the crate boss is actually a secret performance check up.