Bɛ fɛ vs b’a fɛ

Continuing the discussion from N b'a fɛ ka .:

Hello, I have been noticing mostly in Jula the use of bɛ fɛ instead of b’a fɛ. I thought that this is not possible because is a post position. I forgot where I saw this other than a video in Jula so I went to look in the campus. Can you help me explain this? Thanks.