The Shoelace documentation says submit buttons can also have a name and value, which are submitted with the form data.
https://shoelace.style/components/button#properties

For me this is working fine and very convenient. One user pointed out to me he used a form reset button and after that, those name/value pairs are still submitted, but the value is empty/undefined, caused by the reset functionality of the form.

Is there any way to prevent the button value from clearing?

For what I read, standard inputs will be reset to their defaultValue after a reset, which is the state after initial page load.