[Edi]

Sometimes the search algorithm skips provinces. I notice this a lot, because I don't use automated monthly casting, preferring instead to use targeted selection. The automated targeting algorithm is still used to determine what province is suggested.

Most often the skipping happens when the provinces in question are very near the edge of the map (e.g. in Cradle of Dominion some of the southernmost provinces are almost always skipped), but I've seen it happen in the middle of maps too. And it's specifically provinces that should have been automatically targeted.

So yes, we're talking about a legitimate bug here. Investigation would require sending game files to Illwinter for analysis (preferably vanilla game files). But as bugs go, this is not a showstopper, so a fix may be low priority.