For around the past 2-3 weeks, kenkoooo, the website we use for AtCoder problems, hasn't been working.

ABC432 and 433 have been 'registered' by the site, but their problems don't appear. ABC 434 and 435 don't show up at all. There was also an ARC that occured that hasn't been updated on here.

Has there been a change in AtCoder's API that might have caused this? kenkoooo, could you please let us know what's going on?

There also seem to be GitHub issues reporting the same problem:

…but none of them have received a response yet.