That would be my plan B. Plan A would be turn up my politeness and niceness knobs up for a little while. Maybe they're going through a rough time and it's temporary. After a sufficient amount of time to ensure it's not an anomaly, then go for the direct conversation. It usually pays off to give the other person the benefit of the doubt for a little bit, but not forever. It stopped me from being so reactive.
At work? Tell them „I know you don’t like me, I don’t like you either, but let’s just be professional here and then go on with our lives“
That would be my plan B. Plan A would be turn up my politeness and niceness knobs up for a little while. Maybe they're going through a rough time and it's temporary. After a sufficient amount of time to ensure it's not an anomaly, then go for the direct conversation. It usually pays off to give the other person the benefit of the doubt for a little bit, but not forever. It stopped me from being so reactive.