action attribute on submit tag not working as espected

I have one project running with struts and the bellow situation works fine with 2.5.29 version:

jsp:

<s:form>
  <s:submit action="myAction"/>
</s:form>

struts.xml:

<constant name="struts.mapper.action.prefix.enabled" value="true" />

<action name="myAction" class="com.foo.MyAction" method="executeMyAction"> 

The form is submited and hadlered by the executeMyAction method, as espected.

When upgraded to struts 6.0.3, the submit is ignoring the method mapped for this action and is invoking the previous method from the value stack. And I'm getting a "method not allowed" error.