Welcome to Vodafone Community
Can you check that the content bar has been deactivated in your myvodafone.
Also check any security software allows adult content.
Vodafone has securenet which maybe hindering access if you have this.
If all looks ok at your end with all your settings then give Customer Services a try via Live Chat or 191 from a Vodafone phone and they'll double check your settings.
The Vodafone Social Media Teams via Contact-us-for-account-specific-queries also have account access.
A Vodafone Highstreet Store can also help if you take some ID with you.
They helped me recently to remove the content bar as I prefer not to use a Credit Card so couldn't prove my age and I wanted to use a betting site.
Current Phone > Samsung Note 10+ 5G _256Gb > Model: SM-N976B.
Samsung One Ui 2.0 / Android 10.
Samsung Gear s3 Frontier Watch.
Samsung Galaxy Buds.