On my R2, the meter sometimes won't react to changing of aperture once the initial reading has been made. It's like the first reading has been locked in. Once the meter times out, it's receptive again to the new settings. It's a bit of a pain but the camera part works fine.
“Believe nothing, no matter where you read it or who has said it, not even if I have said it, unless it agrees with your own reason and your own common sense.” – quote
I myself am made entirely of faults, stitched together with good intentions. -quote