The photogrammetry “melted” buildings or low LOD related problem is not related to the internet speed at all (unless this prevents downloading data altogether). Case in point: take a slow aircraft, fly over a photogrammetry city at 100ft height, pause the sim and look from the outside. You shall have highest LOD resolution on your buildings like the picture posted above:
The problem is most likely only related to LOD ring distance and there was a long discussion post Q&A about this. Hopefully the developers are now aware of the issue and are looking into this.
For a complete picture (no pun intended) of all the LOD bugs I’ve extensively documented and illustrated: