Just an FYI:
After deleting design options (or merging with the active model), the elements on the missing design option may be visible but unselectable.
Check your passive design options - whether they're set to Locked or not. This may be the reason these objects are unselectable.
Operating system used: Windows
ArchiCAD 28 | Win 11
i5-12500H | RTX 4060 8GB | 32GB RAM