Jump code only works once

My students and I are having trouble with having a character jump more than once. I have followed the code on Game Design Help (Tynker Support) and I also tried practicing with the “Jumper Man Game” template. After pressing the key assigned to jump, the character does not respond to the jump command anymore. There does not appear to be any other keyboard commands that are in conflict. Is this a glitch or do I need add something else? Thank you for any assistance, I’m so frustrated!

I have included a project by one of my students for review:

Did you ever figure out why this is occurring? I am having the same issue and cannot figure out how to fix or prevent it.

I did not, but I was referred to a support staff member. We never got a chance to follow-up, but that was my fault. Let me know if you discover anything new, or I can be contacted privately for the name of the contact I spoke with.