Suspicious of motives
You offer to help with a project and they ask what you're really after. A team-wide pay rise is read as a ploy.
Rule out first
Real past betrayals, by you or the organisation. A political culture where suspicion is accurate. A different cultural baseline of trust.
What could explain it
Mistrust/abuse schema: Suspicion relaxes slowly with consistent behaviour, and they can say where it comes from.
Projection: They suspect motives that match their own way of operating; they're scheming and see schemes.
Paranoid personality: Lifelong, across all relationships, and evidence of goodwill gets reinterpreted as cleverer deceit.
Complex PTSD: Linked to long-term harm in childhood or a relationship, alongside shame, mood swings and difficulty trusting.
Psychosis: The suspicion is bizarre or fixed (being followed, messages in emails) and arrives with other changes in thinking.
A next move
Be consistent for a few months and see whether it eases. Easing means schema or history; reinterpretation means paranoid trait; strange or new beliefs mean a doctor.
If it’s you
When I suspect them, am I seeing them or seeing myself?