Why is content filtering blocking harmless sites on my home broadband?

Hi all, not sure if this is me being daft or Nexora's content filtering. I've got the family-safe setting on for my home broadband and it's suddenly blocking random stuff like a recipe blog and a local swimming club site. Nothing dodgy, just normal pages. I only turned it on because my son keeps getting into weird video sites on the telly. Is there a way to keep the filter on but stop it being over the top? I don't want to switch it off completely.