Do you think if somebody is a Doctor of something ( has a doctorate, not medical doctor) that you should address them as Dr when talking to them?

🤔...............I work with Ph.D.'s.......... Sometime I refer to them as DR.........But most of the time I address them by first name........Most of the time they call each other by first name and sometimes they say Dr...........If I'm introducing them to someone they have never met or it is a business related introduction, I always introduce them as DR..........in a professional environment it should be DR..............