search.maven.org is the legacy search platform with an uptime of 95,88% in the last 90 days (see https://status.maven.org/).
central.sonatype.com is the modern search platform with an uptime of 100%.

So please change the default of centralUrl to https://central.sonatype.com/solrsearch/select