Mission Help Please

Just bought SF4AE. Have been having some trouble with mission 15, can’t seem to get the Flat to hit after M. Am using the L banishing flat cuz its the quickest, watched youtube videos on it and looks really simple. But it feels like the lag from the M hit after jumping H is too long for me to get the flat in. Is there some buffer I should be doing in between moves to land the ban flat after M? Have even tried practicing grounded M to L Ban flat but still unsuccessful.

Hey man. When doing this challenge ( and many others ) its important to figure out which normal is used. Standing Medium Punch can mean a couple of things. In this particular case, its close medium punch.
You can easily cancel this into medium punch green hand, just try to think that you cancel it exactly when the standing Medium punch hits , and you should be golden. Hope this helps.

How exactly do I cancel close medium into the green hand?

Go as near as possible to the dummy. Press medium punch and instantly input the Green Hand command and execute with lp, mp or Hp Green hand. Every Green Hand combos (lp, mp, hp) after its cancelled from a medium punch. If the Green Hand doesnt come out, you are probably doing it too late.
Try to realize the concept of a cancel. Every punch has a start up time, active frames and recovery. You have to cancel the close medium punch in its active frames, not in the recovery time.

Ok ty I will try that

Try pressing f.mp and just continue with the gh motion using mp again. So basically just do a gh motion but press mp when u press forward.

Yea I was able to get it on the first try by doing that cancel described by tonsetzer. Ty, now i just have to get the timing for the EX Green Hand after the 4Lk on mission 18 lol