If he’s chewing something, does it count as a settle?

Hi, I have a 1 year old GSD mix who's overstimulated every time he see us. We have him on our backyard, but we check on him multiple times during the day and let him roam free a bit inside the house.

I try to give him enrichment, exercise and actual training every day, but it doesn't seem to be enough because I'm having a hard time teaching him to settle. I can stay with him an entire hour in the backyard doing nothing, but he just moves around picking stuff to chew.

We have cameras and we can see that when he's alone he doesn't have problems settling, but every time some of us go outside it's like a never ending loop of chewing-resting 1 minute-grab something to chew and repeat.

Could it be that he's settling while he's chewing stuff? Imo he's still aroused, otherwise he would sleep just like he does while we aren't around.

Help me please, I really need some tips on training settle

(PD: he neither sleeps with us present)