It’s looking like I will soon be leaving a role I’ve been in for a couple of years to go to another job. My reasons for wanting to leave are multiple but centre mainly around how unwelcoming the rest of the team have been and the way I’ve been spoken to by my manager on a number of occasions which led me to look elsewhere. What reason do I give for leaving - both officially and if/when colleagues ask during my long notice period? I don’t want to be unprofessional.