Did read the manual? There's an adjustment to avoid that.
As there are different stations, there are also different readings.
After first flash, you shouldn't adjust the temperature high, because it needs calibration.
And before entering calibration, you should go into calibration adjustment.
Why? Imagine that the default calibration step for 350°C sets your tip at 480°C. What will happen in the 450°C step? It will burn the tip for sure.
It's impossible for me to know what your station will read.
And nobody is helping by giving any feedback with calibration results, so it's the best I can do.
People simply install the firmware and go away, or complain here about something that is been said a lot of times.
I can't make it better that way...
So enter calibration->adjustment, and there adjust the values for the 250°C, 350°C and 450°C steps.
These values are applied in real time as you adjust them, so be careful. Move them slowly and carefully monitor the tip temperature. Once you get +-10°C, it'll be enough.
Doesn't need to be very precise, the calibration itself will do the fine job.
Once you adjusted them, save, and run calibration (Start).
Adjust the mesures temperature when asked, but wait until the tip temperature stops moving, it can take 10-20 seconds.
About the screen flip. It wouldn't be hard. Is you screen flipped? It would be the first case I'm aware of.