Who is your ISP's DNS provider?
Do they run their own resolver, or rely on an extant service?
Do they run their own resolver, or rely on an extant service?
I'm reticent to disclose my current DNS provider,
given that I am able to access archive.is and many are not at this point of time.
Edit
I have just checked 9.9.9.9 and they are serving the correct response now. (incorrect earlier)