Restrictions to all websites?

Turn off Restrictions/Screen Time.

Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support

Please read If Safari doesn't load a page or webpage items are missing - Apple Support.

Needless to say, if you are using any non-Apple "anti-virus", "cleaning", or "Internet security" products including "banking security", anything at all in that broad category of utterly useless garbage, don't. A lot of things won't work if you do.

Try double clicking the Home button and swipe Safari upwards. Go to Settings/Safari and clear History and Website Data. Open Safari and test.

Safari - Clear the history and cookies on your iPhone, iPad, or iPod touch

Safari website data on your iPhone or iPad - How to clear