If your personality changes every time the room changes, people start wondering which one is lying.

Adjusting your register for different company is normal and mostly kind. What unsettles people is when the adjustment goes all the way down, so the opinions and loyalties change too, and nobody can work out which version they are dealing with. Consistency is not rigidity; it is what makes you predictable enough to be trusted.

Pick two or three things about yourself that do not move regardless of the room. Let the tone flex and leave those fixed. If you notice yourself agreeing with whoever spoke last, one honest sentence in the moment is enough to correct it.