curious warnings in server log

[aliasname]

Am I right in assuming that the warnings like this:

current sort value is '1989'; new sort value is '1999' do come from.

also do appear in the logfile even if defined
mergeFolderAlbums = false
? I do ask because I thought at if defined there can't be warning, so that one gets reminded by the warning to set up minim that way?

Mostly happens upon differnt releases equal albumtitle same artist. But I found some which also seem to apply upon 'Greatest Hits' albums, which surely do have differnt dates for sorting, since not all artists did their greatest hits in a common year?

Or must I look deeping into my metadata since the above mentioned things aren't the issue for the warnings?