In the attached zip the scenario BasicTest2025018SE-hcdb is written using SE version 2025.018 to test the issue is still current.
Database HCDB 150929 is used in westpac BS.
THe scenario is opened in GE 2025.018, three choppers are set in air formation patrol within the group AAS. One DDG unit is split off from group to form ABS and a 4th chopper air formation patrol is set for AAS. ABS has no AC.
The game is saved giving BasicTest-hcdb-A.hpq. The saved game is opened and the 4 air formation patrols are incorrectly described in the formation editor, the class is noted where it should note the patrol type (in this case ASW).
The formation events - both air formation and surface are incorrectly linked to the new group ABS, not AAS.
If run the 4 choppers all crash run dry of fuel.

AIWindow shows that the AIR-PATROL-EVENTS (and the FORMATION_EVENTS) are linked to group ABS but they should be linked to AAS

 

In the above the listed seahawk (with no preceding number) should list patrol type ie ASW

 

THe chopper should have returned to home unit to refuel

 

BasicTest2025018SE-hcdb.scq.zip

This is fantastic, way to go narrowing this down!

I've thought of another level of testing to see if the split off unit has to be the home unit of the AWOL AC. I'll get back on that.

 

Can you test in 2025.019?  I'm not able to reproduce here, I get four properly oriented formation patrols when I load my save.

Ill have a look next day or so.

It's looking good in 2025.019

confirming I ran same procedure form the test saved game and the problem did not occur.

Small miracles, thanks Don!