BlueHeart JumpStrength Issue

[iKNIFEu]

No, this isn't another one of my auto jump issues.
Sometimes pressing up does not make you jump to your maximum JumpStrength, if that's what it's called.
Basically, pressing up in a specific time makes you jump lower than what you wanted, even if you kept holding the up button.

This is what my maximum jump height is supposed to look like:

This is what sometimes happens:

This was hard to replicate. Though, it is easier to replicate using platforms, this usually happens when jumping in platforms or in situations like sans_bonegap1fast.
It's easier to replicate if you jump immediately in a situation like sans_platforms4/sans_platforms4hard, and jumping immediately once you step into a platform.

I might be wrong, but I think this is the reason for this issue:

I tried adding a X multiplied by 0.5 and Y multiplied by 0.5, it fixed the sans_bonegap1fast problem but it didn't fix the platforms one. Please fix this issue.