Hello [mention removed],
Thanks for reporting this.
I was able to reproduce the issue locally in UE 5.5 and newer versions, including the latest 5.6 Preview and Main (CL 42589677). This behavior does not occur in UE 5.4, so it appears to be a regression.
I’ve shared the issue with the internal engine team and created a JIRA report. The issue will soon be visible on the public Unreal issue tracker at:
https://issues.unrealengine.com/issue/UE-291494
Please note that Epic ultimately determines whether the issue will be made publicly accessible, and the process may take a few days. The tracking link might not work immediately.
As a temporary workaround, you may want to avoid using the EditCondition meta tag on single FInstancedStruct properties inside UDeveloperSettings.
I’ll go ahead and close this case for now, but feel free to reply if you have anything else to add.
Best,
Francisco