There is no Django-provided tag named render_field, which means it’s part of a third-party package - something that you or someone else has written.
If you’re talking about the render_field tag provided by django-widget-tweaks, then the issue is that you’re rendering two different things here. A form widget is an input field, and its requirements are different than just rendering the value of a field.
What is going to control this is the type of form field widget being rendered, not the value being displayed in the field. (Also see Monetary amount input)