2005 Hyundai Tucson sticky automatic transmission shifter

Hello all – On my wife’s 2005 Hyundai Tucson, when it starts in the morning it is hard to get the gear shift to line up properly in the reverse and then drive positions and it seems to be getting worse. But after it’s been driven a while, all is fine – which, of course, means that the dealer’s mechanic told my wife he couldn’t find anything wrong. Any thoughts? I think it might be something in the linkage.