Reg.Direct™ no longer supports the use of the Visualforce Page user interface on Account. Please migrate to LWC as soon as possible.
Clickjack Protection for Visualforce Pages
If you enable the Session Setting called ‘Enable clickjack protection for customer Visualforce pages with headers disabled’, Reg.Direct may no longer update when pressing the ‘Update Account’ button
There is an internal redirect operation that is triggered by Reg.Direct when pressing the ‘Update Account’ button and this operation is prevented when the above Session Setting is enabled.
This is not a behavioural issue with Reg.Direct, it is a Salesforce Known Issue: https://trailblazer.salesforce.com/issues_view?id=a1p3A0000003UIfQAM
Until this issue is resolved by salesforce.com, please following the ‘Workaround’ instructions as listed on the Known Issue page.