v12.5.1 - Screen customisation & Multi-currencies

Hello,
This is expected behavior for now.
The multi-currency management is only implemented on native amount/cost fields handled directly by ProjeQtOr. Custom fields created through the Screen Customization tool are currently stored as simple numeric values and are not linked to the currency conversion mechanism.We can study an evolution of the Screen Customization module to support multi-currency behavior on custom financial fields.
As this would require specific development work, this could be considered through a dedicated sponsorship or contribution request if this feature is important for your organization.

Have a nice day,

Possibly you can try to have currencyTest and currencyTestLocal
Framework is designed to manage this automatically.
Not sure it will work as it was not tested outside standard fields, but it mau. It's worth a try.