The reason your electric knife is giving you trouble is the blades. The design is very important as is their sharpness. I have used three different brands of electric knives and have found the Electric Fisherman (Academy $19.00) to be perfect for slicing BBQ. I replace my blades with NEW ones three times a year. It's $6.00 well spent for new blades.
Some electric knife blades leave a velvet like texture on one side of the meat slice. Others bind during use due to wear, meat getting in between the blades and or poor design causing the knife to chatter and vibrate making clean slices impossible.
I own twelve quality knives for my home kitchen and an Edge Pro sharpening system. I carry one knife in my cookbox, a Forschner 10" Scimitar, for emergencies in case I have no power at turn in time. Otherwise I use my electric. IMO High quality cutlery is a very seductive idea but a roll of expensive high maintenance knives are not needed to slice BBQ. One sharp knife to prep the meat and a quality electric knife is all you need. You just have to choose well. $40.00