In your second screenshot, I see “Connection timed out” errors for security.ubuntu.com. These types of errors are directly tied to network connections & availability, and I have to warrant this is a result of the DDOS impacting Canonical’s servers.
I have seen a couple of threads stating canonical/launchpad/etc server availability is hit-and-miss, but I haven’t seen an official statement (yet) regarding full availability.
Relevant thread with corresponding spin-offs: Update concerning DDOS attack on Canonical and Ubuntu