Trying to understand subroutines

[Gi Nattak]

I went to free space located at 010118 (CA/FF18?), so I went with B2 18 FF 01 FE.

This would jump to CB, not CA, since you have 01. 00 is for CA.

EDIT:
Hmm, I see in your pic the jump is correct in jumping to CA, so that must've been a typo.
BUT, you're pic to the right is showing the C0-C1 bank why?!? That's where you put your code? You can only use event space in the normal range of CA-CC, or the expanded banks. I...think... now I'm confusing myself. Anyway I think the issue is you put the code there in C0, and not at CA lol.