goodness we all have opinions.
I would take note of what they have said, and make an appointment with a health visitor too
But I’m also aware that children develop at different rates.
It could be something to do with his socialisation, perhaps he doesn’t see other children a lot, my children never really saw many babies at that age, until I took them to playgroups.
It could be that you don’t check poor behaviour at home, as lots of people don't
All sorts of reasons, without assuming that your child has learning difficulties.
Do yourself a favour and get some more advice, and make sure you play with them, ( not to the extent that they can’t amuse themselves, but sufficiently to be able to play) take them to different settings, and show them how to behave well.
I’ve seen lots of parents, not bothering to correct a poorly behaved child, and if you don’t let them know how to behave well, how can they be expected to know.
Have a look at what is expected of your child at this age, and practise doing these things with your child.
Shapes, stacking, motor skills, and everything else.
All of these things