You can achieve offline buildings in this way:
1. Use Mapbox Building Manager instead of the built-in Building Manager.
https://forum.infinity-code.com/viewtop … 7791#p7791
2. Modify this script to use vector tiles from a local source, instead of requesting a service.
3. Download vector tiles for your area, and put them in your local source.

I'm trying to create an offline application with the ability to show 3D buildings, unfortunately even if I download part of the map, I can't display the buildings because the data about them is from the OpenStreetMap provider, can I somehow download this data and place the 3D buildings in offline mode?