I am still learning about the nuances.

Our IST - KGL flights on TK on a Z fare credited 3,705 SQM.

Our KGL - EBB - IST flights that landed yesterday on a K fare on TK, where we remained onboard in EBB on the same flight number, credited 3,730 SQM.

The differences are obviously trivial but I still have a lot to learn. There are likely to be non trivial instances going forward.