When you have the 3D Detail Level for library components (including doors and windows) set to MVO, then it allows these parts to change their modeling style based on the Model View Options set in your View (or changed manually). In larger projects, this allows turning off extra detail that might bog down model regeneration (such as door knobs); in projects of all sizes it allows changes in representation (e.g. showing a simplified schematic model rather than a detailed version).
The problem comes about when a user (like yourself) is unaware of how the MVO settings are controlling the detail level - AND - when the MVO is set to show a lower level of detail than is expected. Then it's very frustrating because it isn't obvious why the setting shown in the library part preview is not seen in the 3D window.
I've seen this come about in ARCHICAD 22 when people migrate an older project; the MVO are set differently in the new version than in previous versions, and doors will lose their glazing pattern.
In most cases, I recommend keeping the "by MVO" setting however changing the View Setting to use an MVO variation with higher detail, or simply changing the definition of the MVO that is in use for most of the Views to turn on a higher level of detail. That way the library parts are still able to be controlled by the MVO, but in 3D for most contexts the doors show a reasonable level of detail.