Restoring links from CDN by Photon

did you clear all cache after removing cdn?

Yes, all

can you tell me the site url please?

https://horizonmedical.pl/

as I see that you did not disable wp fastest cache

I turned off and removed plug
https://i3.wp.com/horizonmedical.pl/wp-content/uploads/2018/04/ortopedia.jpg

if you disable wpfc, how can it cause such issue? please disable the other plugins . you can detect which causes the issue with this way.

I only used the CDN from your plugin. The links show that the original url paths have not been restored.

if wpfc causes this issue, why are some images served via cdn? why not all? you are searching the reason on the wrong place. trust me please.