All the above adivce is good.
What is confusing to me is that the OP did not mention the purpose of the lesson, how long the pup is expected/desired to hold point,how the lesson is supposed to end and if the pup actuall has stopped pointing and is merely standing his game.
Are you are following a method/program,using a pros adivce or "winging it"?
If he is holding for that long why isn't the lead in your hand?
For a pup that jumps in the lead MUST always be in your hand.
Set the dog up for success.
You must be able to walk up the lead,around the dog, in front of the dog,be able to tug on the lead,gently push his rear forward then either pick the dog up or walk him off.
Teaching whoa and steadiness on birds may be too early at this age but that would depend on the maturity of the pup.
I work with early maturing pups and 5 months,IMO, is too early to steady on birds. Way more important lessons to be taught at this age,IMO.