Need advice: How to pull thinner points/tips out of hotend?  

Need advice: How to pull thinner points/tips out of hotend?

I'm seeing a new problem, and have not tried doing an MMU print since updating firmware to 3.9.0-3421 / 1.0.6-372.  In the last few attempts to print a multi filament object, I will cut fresh tips for each filament, and I am able to load all five filaments prior to the print.  However, once I print and retract a filament, I can't get it into the hotend a second time.
I've figured out that the tips are coming out of the hot end a bit wider than 1.75mm.  I have not measured the thickness, but it is thick enough that I get a lot of grinding and failure to load filament.  This means I'm only able to make at most, four color/material changes.
Has anyone else had and solved this problem?  I don't have a clue how to get thinner retractions.  And the problem showed up with no other changes, which has me even less certain what to start changing to find a fix.