One thing to try before concluding that a unit is bad would be to reflash the firmware, in case something has gotten corrupted and to be sure you are running current code; this is important in these computerized instruments.
I have had to do this with >$500K Keysight analyzers (they have a convenient recovery partition on their Windows installation), it is not an uncommon occurrence. If it can happen to them.....
73, Don N2VGU
Donald S Brant Jr