Recently, I was getting this ‘low bandwidth’ pop up notification on every flight, regardless of location, which was degrading the surrounding graphics/textures.
The reason behind this is likely corrupted files, especially if you have installed MSFS 2024 during the first few days of launch.
The fix is - for Steam users, run ‘verify package files integrity’. It will re-acquire 2-3 corrupted files. For XBOX and other users, you might need to re-install MSFS 2024.