agreed about DX Eng, I have never had any issues with them not standing behind the products they sell.
something you may want to ask them about,......
there are 2 different software Vers for the 259-b. see if yours is the "latest & greatest". a new software install may fix the issue , but, it sounds like it is the actual meter movement that has gone south.
are you near a commercial AM radio station?
also, there is an analog meter calibration procedure available, but,.... unless you have the proper equip/capabilities, it is pretty in-depth.
the first thing I would do, is to just open the case and look for the "famous MFJ cold solder connection" on the meter leads.
if it is still in warranty, I wouldn't do anything except to look for cold solder joints before sending it to DX Eng/MFJ.
good luck
