Yes I think it is just a Microsoft programming bug that they are unable or unwilling to fix. I did find a solution (if you would call it that). In Indexing Options, Indexing Options> Modify - un-check Microsoft outlook. That's right un-check it. Search then works. Microsoft Outlook will tell you there is a problem when you do search and it that it cannot search but it actually does. (for me anyway).

I wish Microsoft would fix their bugs - they go on about how amazing there software is an then cannot even solve an mail index search problem.