How can neighbours better support a child with ADHD and stimming?

[TheNewFinch]

A child in my neighboring apartment often grabs attentions of people in the building due to his behavior.
The staff of the building gets annoyed and complains a lot and as his mother really gets her sons state, she calms them down but this cannot prolong for long time.
He sometimes have excessive flapping of hands, tapping feet and stimming and is diagnosed with ADHD. The guard at the time of interaction with the child loses his cool and scolds him, similarly the maids working in their house misbehave with the child and I really feel bad for him. They cannot understand his condition but his mother being a friend of mine shared her feelings with me and was sad about it.
Can these children not normally stay a part of the society and till when they would be treated this way?

she should get a new maid, seems fairly obvious

And complain about the guard, again fairly obvious

Given you say you’re a child therapist @TheNewFinch , I would think you would know better than most

The issue here isn’t with the child it’s with the staff I presume the mother is employing?