Hey @shrek - do you have access to a VPN? If so, can you connect over wifi through your VPN and try logging in/syncing?
If that worked, I would wonder if the Bitwarden servers are filtering your IP - I have seen this sort of thing happen with clients when they repeatedly entered the wrong password into their mail apps and the server blacklisted them automatically. Perhaps this is something the Bitwarden folks (e.g., @SergeantConfused or @tgreer) could comment on?