Andy Bernard became extremely unlikable in The Office season 9, and a few factors explain why The Office ruined Andy. Ed Helms played Andy since the character's introduction in season 3. Originally an employee at Dunder Mifflin's Stamford branch, Andy relocated to Scranton when the two offices merged. Though he tried to make a great first impression on manager Michael Scott (Steve Carrell), Andy turned out to be a terrible salesperson. Still, Helms' character was made manager in the final two seasons. His increased role at the company coincided with Andy's drastically different personality.

https://screenrant.com/office-season-9-andy-bernard-unlikable-reason/