Why are you able to block using guy's j.mk on safejump, but get it stuffed when you jump in with RH?

I’m referring to the backthrow safejump btw. I’d appreciate any advice.

It doesnt matter what normal you use, if the jump is safe, you’re safe. You’re probably just inconsistent with the setup (whichever setup it is, you werent specific) or you’re forgetting to hold block, or you’re using the setup on the wrong characters, or you’re inputting an option select while the jump in normal is pressed too late.

Hurtbox varies between different normals so that could be the answer, though I don’t know if that is the case here. I mean if it’s a four-frame safejump it’s going to work against four-framers regardless of its hurtbox, but there are setups out there to beat 3-framer shoryukens as well, which is obviously impossible to do the conventional way (1 active frame+2 landing frames = the time it takes for srk to start up).