Exclude .asp from url rewrite

[experience]

I've installed a new wordpress website

In order to get friendly links on the website i have added the following code to my web.config - however my existing .aspx page wont post unless i remove it

When i click the submit button the page reloads

Any idea how to fix it?

    <rewrite>
      <rules>
        <rule name="wordpress" patternSyntax="Wildcard">
          <match url="*" />
          <conditions>
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
            <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
          </conditions>
          <action type="Rewrite" url="index.php" />
        </rule>
      </rules>
    </rewrite>

[experience]

I think i add need to add a 2nd rule to stop .aspx pages from being redirected

I've tried the following but it doesnt work

  <rule name="san aspx">
          <!--Removes the .aspx extension for all pages.-->
          <match url="(.*)" />
          <conditions logicalGrouping="MatchAll">
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
            <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
          </conditions>
          <action type="Rewrite" url="{R:1}.aspx" />
        </rule>

[experience]

Have tried dozens of combinations without success :frown:

I would have thought adding this would have excluded all .aspx pages but i'm not sure why it wont work

 <add input="{URL}" negate="true" pattern="\.aspx$" />