I have a 2013 Fusion 2.0 Ecoboost AWD. I'm having low load converter slip around 2k rpm at normal to light acceleration. I can feel a slight shudder and I started my log early today and sure enough it slips a little around 1900-2100 rpm. Below 1800 or above 2200 I never notice it. If I let up on the throttle or get heavier into the throttle the shudder goes away. It's not bad, but it's enough for me to noticed it. Converter doesn't slip at WOT once locked.

FYI, trans fluid was changed this summer. I've attached the stock file for reference.

2013 Ford Fusion 2.0L AWD STOCK.hpt