Something that I don't understand....

[.]

Here's a level I made, but that's not the main point of the thread.
In the first room of Insane Mode, Viridian gets killed side spikes of the little block by moving to the right but not when moving to the left.
It seems strange to me, so I want to consult your opinion for the explanation of the phenomenon.
Thanks

[Dav999]

Maybe an off-by-one pixel error in the hitbox? Something I noticed:

If he looks right at the checkpoint, he dies at right spike but not at left spike.
If he looks left at the checkpoint, he dies at left spike but not at right spike.