Migrating kleopatragroupsrc to new location worked for update 3.2.2.0 to VS-Desktop-3.2.93.33-Beta on Windows.
kleopatragoupsrc in old location is not deleted, but a copy is written to %APPDATA%/gnupg/kleopatra

But when trying to make changes to that group it first looks as if it is possible (I removed half of the 6 certificates and renamed the group) but after closing the group configuration window and opening it again the renaming was still there but it was again 6 certificates in the group.
A new group can be created but again can't be changed persistently.

This is for the new location, the file in the old location is not updated at all, as expected.

In Debugview I see, after only opening the group configuration dialog:

31	1043.134342	5624	kleopatra.exe	org.kde.pim.kleopatra: GroupsConfigDialog(0x51051f0) loadGroups
32	1043.135916	5624	kleopatra.exe	org.kde.pim.kleopatra: open_or_raise showing window

After opening the group for editing:

33	1074.372279	5624	kleopatra.exe	org.kde.pim.kleopatra: GroupsConfigDialog(0x51051f0) saveGroups
34	1074.374000	5624	kleopatra.exe	org.kde.pim.libkleo: Updating group "neue Testgruppe 1" (id: "hZlZ3oBP", source: 1, keys: 2, isImmutable: false)
35	1074.374099	5624	kleopatra.exe	org.kde.pim.libkleo: writeGroup Writing config group "Group-hZlZ3oBP"
36	1074.374712	5624	kleopatra.exe	org.kde.pim.libkleo: Updating group "test-pgp3" (id: "liXIAFgt", source: 1, keys: 6, isImmutable: false)
37	1074.375772	5624	kleopatra.exe	org.kde.pim.libkleo: writeGroup Writing config group "Group-liXIAFgt"
38	1074.375862	5624	kleopatra.exe	org.kde.pim.kleopatra: onKeysMayHaveChanged ignoring changes caused by ourselves
39	1074.376028	5624	kleopatra.exe	org.kde.pim.kleopatra: GroupsConfigDialog(0x51051f0) loadGroups

And then nothing at all while making the changes and clicking "Save".

In contrast, in an older version where changing the group works, the order is as expected, write is executed after making changes and not before.

I have opened T7268: Kleopatra: Existing groups are not saved after editing them for the issue that was found while testing this ticket. The issue is a regression caused by changes made for T7233: Kleopatra: Certificate details dialog non-interactible when opened from group edit dialog.