Thank you for replying,
This one is somewhat strange, actually.
Here is a resource:
https://fascinators.b-cdn.net/wp-content/themes/Avada/includes/lib/assets/min/js/library/jquery.placeholder.js
On my browser (Chrome in incognito mode and I am not logged into the site), I can see:
Cache-Control: public, max-age=31919000
This is expected — about a year expiry.
Testing same resource with external cache checker (https://requestmetrics.com/resources/tools/http-cache-checker/), I am getting
Cache-Control: public, max-age=604800
I do not have Expires header.