Has your DNS change been picked up everywhere ? Check across several resolvers.
When you change a DNS record, it takes a while for the change to spread across every resolver on the planet (because of caching / TTL). This tool queries several public resolvers at once to see whether the new value has been picked up everywhere.
From a few minutes to 48 h, depending on your record's TTL. Lowering the TTL before a change speeds up future updates.