I used to have a digital vacuum gauge on the dashboard that read inhg correctly with my 327 adaptor.
Due to corruption of the dashboard wrt horizontal spacing, I reinstalled the pro app but now can not get the gauge to read correctly: I get Vacuum / InHg but the reading looks like psi.
I have tried changing the preferences and unit settings as Ian suggests with no success.
I just read another post which says someone found that an analogue gauge reads correctly but the digital gauge does not.
Has a bug been introduced?
Has anyone else had this problem, or the dashboard display corrupting?
The export / import function does not seem to help.

Update: I have tried a combined analogue / digital gauge and they both work, so the problem is with the digital only gauge.