Over-apologises
'Sorry, sorry, just a quick one, sorry to bother you.' They apologise when you bump into them.
Rule out first
Regional or cultural habit; British 'sorry' is often punctuation. Junior status in a strict hierarchy. A real error.
What could explain it
Agreeableness: Warmth runs through it, and it doesn't stop them asking for what they need.
Fawn response: It spikes when someone is irritated or powerful; they appease before any threat is stated.
Defectiveness/shame schema: They apologise for existing rather than for acts: for taking space, having needs, being there.
Approval-seeking/recognition-seeking schema: Each apology comes with checking ('is that okay?') and a close watch on your face.
Undoing: The apology follows something they said with an edge, as if to cancel it out.
A next move
See whether they can make a request without the apology, and what happens when you're visibly annoyed. Calm under annoyance means habit; collapse means fawn or shame.
If it’s you
What am I apologising for: something I did, or that I'm here?