A site that I'm using recently switched from old POST forms to a React component using AJAX for updates to the back-end.

Previously, I had a Tampermonkey script doing some calculation to update a lot of the form's fields by setting their value property and then submitted the form. This worked fine but it seems to have no effect on the new React version. The form fields are updated, but the values are not propagated into the React component and therefore not updated on the back-end when the update is launched. Instead, the values are just refreshed to the old value after the update by React.

So, obviously setting the value property is not enough. But I have no clue what to do. I'm not a Javascript/React wizard.

Any ideas on how to update the form components correctly through my Tampermonkey script?

/Jan