[UE5-03] Mesh positions update in blueprint not displaying in viewport - any ideas?

Using latest UE5.03 - I have a Level with:
A blueprint inside named BP_floor_3 - this contains some blockouts and basic shapes
One of the rooms on floor 3 I am designing properly so I created a new blueprint - BP_F3_Room1 which is positioned inside BP_Floor_3 correctly.

Inside my BP_F3_Room1 I have a number of simple cubes.
If I modify the scale, this is always reflected accurately in the viewport (e.g. simulation or ‘run in viewport’).
If I modify the rotation of a cube - this is sometimes reflected accurately in the viewport.
If I modify the position of a cube - most cubes are reflected accurately but some are never updated in the main viewport. E.g. I can have 10 identical cubes in BP_F3_Room1 - 7 of them move fine and are updated in viewport. 3 will never be repositioned in viewport no matter what I do.

If I look at BP_F3_Room1’s BPviewport - or BP_Floor3’s BPviewport - all cubes are accurately reflected in terms of position, rotation and scale.

All objects in all BPs are children of DefaultSceneRoot. No roots have any scale/position/etc applied.

As one particularly annoying example - I rotated a cube 15 degrees, ‘undid’ the action - but in the main level the cube shows rotated 15 degrees and refuses to update even if i rotate again.

This would be annoying - if it wasn’t for the fact I cannot find any way to have the level accurately reflect the BPs. Restarting UE, rebuilding all geometries etc - nothing fixes it.

I have tried:
Changing all meshes to be static, stationary, moveable. Rotating, rescaling, reposition (scaling still applies accurately, the other two are intermittent or never applying as mentioned).

Any help to force an update of the BP into the level would be amazing!