Thanks for sharing both the symptoms and the fix.
My pleasure.
To expand on this issue, I do recall when I tore the meter apart to recap and clean, the display assembly has the elastomeric strip in it, (ref MP14 in the manual).
The strip is 2" long and had been somewhat flattened and distorted due to the shape of the assembly and pressure.
I do recall rotating it so that the oblong side of it sat vertical between the lcd and the control board.
Not a correct fix, but until some type of replacement for that piece can be found, the meter will probably have it's finicky days.