The change appears not to have worked.
CHECK WHERE YOU MADE IT
If your nameservers point at an external provider, cPanel records are ignored.
This accounts for most cases.
WHOIS shows which nameservers are actually in use.
CHECK IT SAVED
Look at the zone again. Is the record actually there with the value you intended?
CHECK THE AUTHORITATIVE ANSWER
Query your nameservers directly rather than relying on your usual resolver.
If they return the new value, the change is made and you are waiting for caches.
CHECK YOUR OWN DEVICE
Browsers and operating systems cache DNS.
Try a private window, another browser, and mobile data.
CHECK THE TTL
A record with a long TTL takes that long to expire everywhere.
CHECK FOR A CONFLICT
A CNAME cannot coexist with other records for the same name. A conflicting pair produces unpredictable results.
CHECK FOR A DUPLICATE
Two records for the same name with different values.
THE DIAGNOSTIC THAT SETTLES IT
The authoritative query. It distinguishes "not made" from "waiting".