@Flaminkate: I'm not sure. Do you encounter any restrictions when using Wi-Fi, or is this happening while using Mobile Data? If it's the latter, please reach out to your network directly to further your enquiry, and an advisor will be able to look into this further for you.
Perhaps check with your mobile network that they haven't got any type of content lock activated on your account.
And speak with the website team of those sites to let them know your experiencing some issues @Flaminkate
Current Phone > Samsung Z Fold³ 5G.