Mirage 2015

[cjcj44]

2015 Mitsubishi Mirage 112,000 miles automatic:
Car jerks when starting out then smooths out.
Had transmission fluids changed, oil change, plugs replaced and air conditioning recharged, after doing this seemed to get better then started doing same thing again a jerk in low rpms.
Just yesterday in cruise about 60 mph the engine rpm’s revved up hit brake and it stopped this.
Mechanic I have taken to cannot figure out what it is (no codes show up on diagnostic). Any ideas?