I'm getting the exact same issue WiFi speed data speed allot slower and I cannot boot into recovery mode or download mode at all it just says PDP backup fail setup-wizzard finished.
Samsung NEED to fix this One UI 3.0 I've had non stop issues since updating and it getting worse appart from unable to get into recovery mode or download mode my phone is now freezing up and lagging I'm getting frame drops on games and the ram management is TERRIBLE worse update samsung thanks for breaking my galaxy s20
Same issue. For some reason particularly bad when browsing with Chrome and Samsung's own browser frequently failing to connect - despite other apps - Mail, WhatsApp, Facebook - still working. Hugely frustrating.