For what it's worth, I'm not experiencing this with Peacock. It's downloading at 1080p for me.
However, I have experienced something like it in the past and it was because of a corrupted update that was done through the StreamFab update utility. If you've updated via the update utility, it's possible the same is happening on your machine. To correct it, I made a backup of my StreamFab program data folder (so as not to lose my queues), uninstalled StreamFab and then reinstalled with the full installer (not the web installer - you can get the full installer here in the forum). Once the reinstall was complete, I opened up StreamFab to create its folder structure, then exited the app, and restored the StreamFab program data folder. Not sure it'll help your situation, but I give the information freely.
Good luck and let us know how it turns out.
