Each of the few times I've taken a Myers-Briggs test, I've gotten a completely different score each time. I don't think these tests measure any immutable attributes of personality, they measure preferences which can change with time and social circumstance. And getting a new job is obviously a change of social circumstance..

Agree. And people also tend to answer in different ways (how I am, how people think I am, how I want people to perceive me, how I want to be, etc), depending on the circumstances and environment of the test.

I don't think it has much value beyond some sort of throwaway catalyst for conversation.