I have also managed to over tighten mine to the point when it clicks and it goes slack and you think oh no, tried tightening it to a tight spot and seemed ok but checked yesterday and it had managed to loosen itself, called down the local Nissan dealership which truthfully virtually never used for a new cap and discovered that looking at the parts diagram there is a second part to it which is separate called a seal which you cannot see from the top when cap off obviously only visible once you have removed the plastic cover. Have ordered that as well coming from the Netherlands strangely but on the face of it that could be the part which threads have gone if so then the comments about plastic cap stripping a metal thread may not be strictly accurate, the only issue I can see is that the strengthening bar needs to be removed to get at one of the bolts holding the top cover on 🤷♂️