When I sprint(jump) and press six it has no effect. I tried it in survival but I think it's in creative too.
What I expected to happen:
Select slot 6 in my hotbar.
What happened:
It didn't select slot 6.
Steps to reproduce:
1. Sprint(Jump);
2. While sprinting or jumping select the sixth slot in your hotbar, nothing will happen.
Related issues
Comments
I expected that it will select Box 6 in my hotbar
Then, unfortunately, I can not reproduce as when I sprint jump and press 6 it switches as it normally does

It happens with my Minecraft as well. Another example I have is if I press tab to view the player list while sprint jumping, the list won't appear until I stop sprinting or stop jumping. What kind of keyboard are you using?
It's called Logitech K260

Is it wireless?
Yes

That might be it then, my keyboard is wireless too. Th3F4114n0n3, is your keyboard wireless?
What are you expecting it to do?