So I found out what the problem was. The last working item before it rolled over to the first item again contained a Swedish ÅÄÖ character in the title, and therefore in the url. If i change the title and remove the Ö for example it works and the link to he item looks better as well.
I’m guessing my best bet is to add another field into the content manager and use that to display names (with ÅÄÖ) and keep the title field for generating urls and remove any special character from that field.
It’s an OK workaround i guess but took some time to figure out and im not sure if its documented anywhere.