My company just updated from 2024 sp5 to 2025 sp5 and several instances of hidden geometry have suddenly become visible when they should be hidden. This only seems to happen in assemblies. The three types of I have observed doing this are planes sketches and curves. So far I have only observed this with files updated from the old version to the new version.

There are two causes I have seen for planes, one was a sketch plane(?) for a thread feature in a part (the plane was not in the feature tree). This one would appear after opening the part from the assembly after the part file was rebuilt it would disappear but would stay in the assembly most of the time. I remodeled the one part I observed this in to use a cosmetic thread feature instead and it no longer has any problems. The second cause I have found is that making some subassemblies flexible causes all planes to become visible in the assembly and unable to be selected and hidden in the graphics view. The planes are also marked as hidden in both the feature tree and pop out appearance pane (don't know the actual name of this pane).

Image of subassembly being flexible

Image of subassembly when ridged

Next, the problem I have for sketches seem too be assembly file specific. as I had three files all using the same subassembly but only one of them had the sketches of the subassembly become visible when they were hidden. All files were even using the same configuration of the subassembly. When this happened I was frequently unable to select any of the lines in the sketches but if I was I would be show the sketch. If I showed the sketch and hid it again nothing would change. The solution I have found that lets them be hidden in the parent assemblies is to delete the subassembly from the top level and re-add it. (I would save and close top level after deleting but before reassembling to preserve all the mates so they can reattach themselves to the subassembly after it is reinserted.)

I don't have an image of the sketches being visible as I have already fixed this problem in all of the files I am currently working on.

Lastly, curves for these I can see them in the top level, and when selected I can track them to a subassembly but can not select them in the subassembly. This stops me from finding out the source of them, as the ones I can see are floating in air inches away from any part not aligned with any round features. I have no idea what created these curves as we do not frequently use features that create curve, to my knowledge. 

Example of the curves floating in air.