My dog is 15 months old and very similar. I can coreect him with an "ah ah" he so soft. Like yours hes not a fearful dog. Leash corrections sometimes shut him down. Although my son can leash correct him and hes fine. I bring a squeeky ball with me and it perks him right up, sometimes he just needs a lets play break.
Dexter Bartolomeo -GSD (24 months)
Fluffy Cornelius - Maltipoo rescue (approx 7yrs)
Squeezette Antoinette- Shih Tzu (16 yrs)