Excitement barking or something else..?

[JudgeMenthol]

I have a 3.5yr old show type cocker - I've had him for 2yrs, previously he was a covid bred puppy who the breeder couldn't sell.
Hes not as bouncy as other spaniels I've had, but no issues that the vet can see. At home he doesn't bark, doesn't bark when someone visits.
He goes to daycare one day each week and happily trots in, tail wagging, no barking.
He barks going into my mums house - approx twice a week - tail wagging, the same when I go to my partners who also has 2 dogs, they all get on. He barks for about 10 mins, tail wagging again, then settles down
My main issue is on walks - he barks at people we pass on the footpath, including people he knows like the neighbours.
He is walked on a big field, mostly off lead, and again barks at people we see who also have dogs. Once he's got past the sniffing stage he settles and will play with the other dogs - I'm not entirely sure if he's barking at the dogs, or the people, or just because he's excited?
Unfortunately some dog owners don't stop to chat or let their dogs play due to this 😕
Anyone had similar?

It sounds like frustration. My terrier can be the same. Engage disengage is great for this. We mostly now can past people without barking unless she knows them.

This is quite a spaniel thing too - they do bark to play, so could be excitement.

It sounds like excitement to me, but lots of dogs/owners don't seem to like it so it may be worth practising some "look at me" type commands to try and stop it.

Thanks all, we'll try some 'look at me' destraction stuff and see if that helps..