Going to ask how you got on today!
I wouldnt worry too much - still got the expected first crack-second crack spread of 20 deg or so. Might read differently on your DMM than others, but Id just adjust your degree expectations to suit your setup.
So drop you gun temp (more than you are currently) 5 degrees or so before your roast reaches first crack (so @ 180deg or so) and try and stretch out the time to second crack to about 5 mins - even if it ends up happening at 212 measured. The temp is just a guage - first crack & second crack are the important bits to log consistently…
But more importantly - how have the last few batches tasted?* :)