There is a main form that has several fragments (subforms). Such fragment object, when you expand it in the Hierarchy view, it is visible but not enabled (not clickable). Also, it doesn't show in the XML view. This is the normal expected behaviour.
Sometime, I notice that some of the fragments become enabled in the Hierarchy view, and you see all the child elements are clickable (enabled). Also, they show when you switch to XML View.
This happens sometimes, for some of the fragments, not all. I am not sure what triggers this issue.
See snapshot below to clarify.
I usually fix this by switching to XML view, and deleting all the children of the fragment, and just keep the first line that points to the fragment. This is time consuming, and since this form is huge, there is a risk that it will crash while switching back and forth, and one time such actions has damaged the file completely, and we had to restore it from the backup.
I did further analysis, and used NPP to compare some of the corresponding parts of the XML Code of the fragment with that of the parent form. I took a snapshot of the comparison results and included it below. Also, I modified the default value of the field "park_mutual_cp201" in the fragment, and it was reflected in the parent form. However, if modify default value in the parent form for the same field, then, further modifications to this part in the fragment will not reflect back to the parent form.
I used to find this helpful, it meant I could have a fragment like an address block then override values for when it was a postal address or a street address or whatever.
Once I had set up the objects I would allow to be overridden I would then make them into a custom object (so drag the object at the fragment level to my custom library) and that seem to fix accidental overrides.
So, I guess you could do that, but the newer versions of Designer don't seem to let you do that anymore, so I'm not sure what editing scenarios creates the overrides.
Anyway, there is a option within Designer that removes them, without using the XML Source view.
Click the palette menu on the object palette
and there is a "Clear Fragment Property Overrides" option.