I think this is zerobytes.monster, one of the reddit mirror instances.

the post count fits and it also matches with the user count not significantly dropping.

that instance has been using rather strict waf blocking rules from time to time that likely also affect the crawler for fediverse.observer.

the second link is just incorrectly linked in the comment, as the colon is included in it. it should be https://www.auswaertiges-amt.de/de/reiseundsicherheit/suedsudansicherheit-244250

with db migrations the database structure changes. it’s not possible to do db schema migrations without downtime unless the application has been built with that in mind and the application is able to run with a partially upgraded schema.