Stornoway are kinda more indie pop than folk but have similarities to M&S. Check out “Zorbing” which is a fantastic tune. They have a new album out that’s got some great reviews.
You might like Tunng (Woodcat and Tale From Black).
They’re kinda…electronic folk? so you might not like everything, but enough is up on Youtube to find some gems.
(All the others I thought of were already listed!)
Oh! Kings of Convenience! Boat Behind