I first noticed this bug when I opened studio this morning but I haven’t been in this team create for a few days so it may have begun earlier. For whatever reason, the work that one of my team members was doing is visible for him but not for anyone else (see image).
Studio Version: 0.444.0.0409999 (for both)
Restarting studio does not appear to fix the issue. I had him copy + paste his build which caused it to become temporarily visible for others but it quickly disappeared again. It may also be important to note that the parts do not exist for anyone but him and cannot be selected in addition to not being visible. As well, these are normal parts and not unions or meshes.
edit: it appears as if their build is visible in-game for everyone, just not in studio