if dirmngr is explicitly configured with a keyserver -- or if it is using the default configuration -- and its host table has *all* of the configured keyservers marked as dead, for whatever reason, then it refuses to make new requests, which causes gpg --search to fail (it tells the user to (use option --keyserver), which is a separate weirdness, see T4512).
marking keyservers as "known dead" is useful when selecting among a pool where some keyservers are dead but others are not. But if *all* keyservers are known dead, and the user is requesting a network connection anyway, dirmngr should go ahead and try one of the dead ones, rather than pre-emptively failing.