CDN integration not doing anything

Hello,

The CDN option isn’t working and I can’t figure out why. Everything seems to be in order, but the files keep getting served from my server instead of the CDN.

My settings in the WP super cache plugin CDN tab:

Enable cdn support – checked.

Off site url: https://****.cachefly.net (there are letters there instead of the stars :))

Include subdirectories: wp-content/uploads

Exclude if substring: .php

Additional CNAMES: empty

Skip https: unchecked

I checked that the files are on the cachefly server and are accessible.
I tried disabling all other plugins except WP Super Cache, but got the same result.

Help?

https://www.ads-software.com/plugins/wp-super-cache/