Genuine question what is the auto pilot problem?

No I dont do high altitude flights. I enjoy the actual piloting activities more. The way you learn when you start flying lessons. Bit old fashioned I suppose. But maybe thats the point what folks describe as the ‘auto pilot’ problem, is infact a FMC issue.
I use all the basic functions you would find in an auto pilot but I perform the FMC function as the pilot.