This is a Bug we stumbled over the last days with a level of ours. Starting it in editor didn’t cause it so we didn’t realize there was a problem until after the level was done. (which made the search a lot harder)
The level designer had this light as a little helper for the building process and forgot it in the end.
Would be nice if there was a filter when packaging that at least warns you that an Object like this is still in the files.