At that age, no, it is not a stage. It is something that needs to be corrected.
Can't really help with the gatoring, because here it stopped at 5 months.
But Hans was quite the jumper in his day.
I had him on a leash and when he even gave a sign that he wanted to jump, I stepped on the leash so he couldn't. I also made a loud and low "AH!" noise.
He learned that this was not OK with me.
I also did my best to get him nice and tired and not to talk to him in a high voice that would get him riled up.
Since he liked to jump, I threw a ball over and over so he could jump for it--- not too high, though. Growing joints need to be managed. Just enough for him to enjoy himself.
If the weather won't permit, you still can do the jump for the ball game in the house.
You can also see if he will search for a toy you hide. All that sniffing and searching wears them out. Good luck.