Corner throw unfly setup problems

Using this setup something strange happens:

FP Throw,,, fly,, f.UPfp, unfly, sj.UPfp, /, [rejump infinite]

Sometimes after two reps of the rejump infinite using the setup mentioned I’m unable to jump until the combo ends. I’ve seen this happen with a lot of flying screen combos but they are usually 100%. This only happens sometimes and I’m at a loss to explain it.

Here’s a video of it happening:


Any ideas?

tried the setup several times. no issues.

though this is not a flying screen combo, I have not seen this stuff happen in FS combos anyway