I think I know the root of the problem.
It is probably your IP being blocked from Osu or some similar circumstances. (Mine got blocked for spamming to log in to my account, out of the blue which I do not remember doing and due to a bug, not sure what caused though.)
Changing WiFi network, changing IP address, using mobile data, using a VPN and other things that can change your IP address that you were originally having problems on should fix this issue. Also, someone managed to fix this by resetting their modem. Because some modems will change it's IP when rebooted.
Surely, after a while, your IP should be unblocked and should be able to play normally on your old network again.
Issues that hints that your IP was blocked are: osu!direct not functioning, unable to load any online scores, unable to submit scores properly.
However, you should still be able to: Connect to Bancho, such as chat and multiplayer.
This is my conclusion to this issue, should work for some people. Sorry for bumping an old thread, since this thread is one of the first to appear on google search, and I think this would further help anyone with this problem.