I have too add, the probes where not like this when new. I have had the meter, several years, 4 to 6, company replacement is not expected. I thought the problem was the banana end and used DeoXit on the banana parts, without any positive effect.
I have included a picture of my probe tips, The seems shiny enough although the tips are dull! The problem shows when I touch the probes together 3/8" from the tips. If I press them together very hard I can get the resistance down to a minimum, sometimes I need to rotate the tip a little to, I'm surmising a lower resistance area on the probe.