My Menu bar has got very thin in Sonoma and I can't change it

I've upgraded to Sonoma and since then, my menu bar is too thin for the content - as per the above. I've tried changing the menu bar size in Accessibility/Display but this had no effect. I can't find anyone who seems to have had the same problem and whilst it doesn't _really_ matter it's very annoying as I can't see things in the bar properly. Any ideas? Thanks!