The answer to this kind of issue has been posted here many times.
Coils develope shorted turns from heat ageing and cause missfire under light throttle loading in OD at speeds between 45 and 60 mph.
These coils will even cause a minor hesitation flutter off ide from a stop but then goes away depending on if the engine heat is acting on them at that moment.
This condition is not a 'hard' fault so won't set a code or lamp you can see..