When that microflow creates validation feedback, switch a boolean value for a variable (“errorsFound” e.g.) and at the end of the microflow decide to show a popup that errors have been found to inform the user could be an option. Or use something like the toaster widget from https://marketplace.mendix.com/link/component/111533 for a more fancy option.
Not sure if this widget still works in your version, but this would scroll the screen to the validation error that was encountered: https://marketplace.mendix.com/link/component/50370
Hopefully one of these options can help out in your situation.