I discovered with an online tool for optimization of a website loading time that the bootstrap css file is being loaded from the host rather than from a CDN. The Settings > CDN has a lock and there are no custom imported/modified theme, I use default one. But also in the Export settings the "use CDN" switcher is ON. And if I open the
header> link then it will show the corresponding CSS file without pointing to external server (though as I understand it does not matter). Anyway please see the screenshot that on the actually published website it is not replaced with a CDN link.