There was a "+" at the start of this number, so part of it may have been changed from the original? I'm not 100% sure on how that works or what it means or anything.
But I called back and got an automated message about it being an "incorrect number" followed by the call immediately ending.
The call came through with a very loud pitched background noise, very strange. As I holidayed this year in Slovenia I answered wondering if there was a connection?