Based on the article
A content delivery network (CDN) is a distributed network of servers
that can efficiently deliver web content to users. CDNs store cached
content on edge servers in point-of-presence (POP) locations that are
close to end users, to minimize latency.
Azure Content Delivery Network (CDN) offers developers a global
solution for rapidly delivering high-bandwidth content to users by
caching their content at strategically placed physical nodes across
the world
What you can do though to fasten the process is to just log in to Azure portal, go to the
CDN profiles
section, pick your CDN
, And Click on Purge on the top menu.
It should automatically update the content of the cache memory for your endpoint/s and you shouldn't wait hours.
Hope it helps. Cheers