Hi James, welcome to the forum and thanks for posting.
This is a weird one because I occasionally get reports of the nvALT extension not working, but usually it keeps working for me.
1) First of all I’ve also just updated the nvALT extension just now - you might try redownloading it although I don’t expect it will make a difference. I’ve just tidied the code a bit. Give that a try so we are on the same page.
2) Assuming that makes no difference…
The way the extension works is by opening a URL like this:
We can do a test to see if it’s PopClip that’s going wrong or something else. Can you try pasting this command into Terminal:
Does the text “example text” get added as a new nvALT note?
If not, what happens? Is there any error message?
(screenshot is Big Sur but I’ve just tried on my Monterey machine too)
Let me know, then we’ll dig deeper.
(Regarding alternatives, I guess nvUltra might be the thing!
Though I’ve not had a chance to try it yet.)