Additional css not working

Hi,
The changes that I’m making in the ‘Additional CSS’ seem to work while I’m in the customize pane, but when I go to my site, they are not working. I’m changing the colors and some fonts in the widgets in the footers, but I’ve also noticed that the facebook links are not working either. I triple checked the FB url, all good – I closed everything then re-opended them all this morning, it’s still the same. I’ve just created a child theme & will see if I can fix it that way but I thought this is very strange. It is really peculiar to see them take effect one one side, but not on the other.
Hoping you can help,
Regards,
Marita