Please check SAP Note 2080322 where it is mentioned:
"....it is advisable not to recompute /4MI while Retro payroll run."
You can control /4MI recomputation behaviour through the use of the feature 40MWT and INWT. Please check the documentation of these two in your system.
In essense, /4MI once computed should NOT be allowed to be recomputed in retroactive payroll runs in order to make sure that Form 24Q output remains consistent throughout the year.
Regards
