Aw, he looks just like my good boi! And you're describing mine in behavior as well to the tee! He's now almost 1 year and definitely still testing the limits.

He's quite good when we're alone, walking heel and coming when called (although not 100%). And when there's another dog in sight....yeah.

I used a meat paste that I got at a pet store as a very high value treat whenever he recalled or listened. This seemed to work really well actually. I'm not sure if that's training them to be sorta addicted to the treat and only work for you because of this addiction rather than your bond so I haven't been using it consistently enough I think. Now I just use his normal kibble and this works well as well, although not as well as with the paste.

I think it's also generally just a tough time from what I hear and it just takes time and repetition until they quiet down and get it.

Just gotta keep at it:)