I have stock 88.5 Zuk and have an intermitten starter problem. Not the clickity starter version problem! At least once everyday when I crank the engine the starter drive will miss the flywheel ring gear and grinds. When it does this I shift to neutral and the engine will crank. Obviously I have an alignment issue but what causes it? A couple of months ago I found the starter bolts were loose. I removed it to check and the flywheel ring gear looked fine but once retightened it did not resolve the problem. Anyone have an idea what could fix this?

It could be the flywheel ring teeth are worn, or that the starter drive is kinda sticky and isn't fully sliding all the way to engage the flywheel teeth.
You could try removing the starter, cleaning it up with some brake cleaner, lightly lubing the shaft that the starter gear slides on and seeing if that fixes the problem.  If it doesn't, you'll need to look at the flywheel ring teeth.