I bought and finished Hollow Knight some time ago, had good fun with it.

Recently I wanted to try again with the new content patch and all.

However, after buying the map for an area, I can see the parial map that I bought, but nothing more is ever filled in, no matter how far I explore, whenever I find a bench I recall it filling in the new areas I'd visited on the map, but now it is never updated.

Am I missing something, like having to buy a quill or something before you can further expand your map?

Yes, that is exactly what you're missing. (You can buy it, as well as various upgrades to mark things on the map, in Dirtmouth.)

Note that you will also need to find a bench to actually update the map.

Wow, that means I'll have to get my behind back to Dirthmouth again. If I can find my way back.

Thank you very much. Really didn't expect the mapping mechanic to change.

Nothing has changed, you must just be misremembering it. You've always had to buy the quill to update the map. But it's available the very first time you go to the map shop, should be one of the first thinhgs you ever buy.

Geez, my memory must be going then :-(

But yeah, I didn't even go back to Dirtmouth in this game, whereas the first time I played it, I was wandering back and forth not sure where to go next.

Thank you very much

I bought the Quill in Dirtmouth, but have found that when I traveled to the new map in the west the quill doesn't work anymore. Where do I buy the new map? The store in Dirtmouth didn't have any extra maps to sell.

You'll aquire a skill to get through the barrier later. Just go into another area for now.