Not an apex domain
The domain 440D9D51FE6F67773EEE762B2BFC855C.8326AB9E4D56A99B59E0FF58B940DD3F.a835dc0fde1eb76aa0.sectigo.com is not the root of its zone.
Instead, try zone transfer on sectigo.com .
Instead, try zone transfer on sectigo.com .