Iron fitting

My first thought would be to check lie angles in case of a mistake, too upright can cause a miss left. But as you mentioned they were fitted I'd be straight back to whoever did the fitting

That's just a silly response in fairness. Solves nothing

I would say to also check lie angle. Could be they were made flat instead of upright or visa versa and heel is catching first, this can cause left misses. See if its moreso the heel interacting with the ground when you hit a few shots (If your local pro shop has a strike plate or they can check the lie angle etc) or hit a few off a range mat and see if the residue from the mat is on the heel area as opposed to the full sole of the club.

Another thing, what grips are on them? If they are align type grips with the ribbing down the back and they were fitted wrong but it would be strange for each club to be wrong!!

If you got the irons from a local pro or fitter. Go back to them and ask to check the specs match what was ordered. You should ask for a few mins on trackman or sim to confirm.

If you bought them via a shop the same should apply. However if you bought them online like DTC as your own spec, it's on you to test and prove the specs match what was ordered.

While the spec could be wrong, it's most likely the club lines up slightly different to your eye and subconsciously changes your path.

Interested to hear how it plays out for you.

How consistent is this miss? Has it been a couple of rounds/range sessions or happened to be on one day?

Have you contacted the fitter yet, could be too upright and an error in production rather than fitting error.

Be interested to know your spec