Edit rule with API

https://docs.sophos.com/nsg/sophos-firewall/18.5/Help/en-us/webhelp/onlinehelp/AdministratorHelp/BackupAndFirmware/API/APIUsingAPI/index.html
https://docs.sophos.com/nsg/sophos-firewall/18.5/API/index.html

I already followed the steps and I can do many things, but what I can't do is modify an already created rule to add more devices, I have this code and it doesn't work.

<Request>
   <Login>
      <Username>API Admin</Username>
      <Password>xxxxxxxxx</Password>
   </Login>
   <Set operation="update">
      <FirewallRule>
         <Name>Clone_MacTracsa</Name>
         <Description />
         <IPFamily>IPv4</IPFamily>
         <Status>Disable</Status>
         <Position>bottom</Position>
         <PolicyType>Network</PolicyType>
         <NetworkPolicy>
            <Action>accept</Action>
            <LogTraffic>Disable</LogTraffic>
            <SkipLocalDestined>Enable</SkipLocalDestined>
            <WebFilter>none</WebFilter>
            <SourceZones>
               <Zone>LAN</Zone>
            </SourceZones>
            <DestinationZones>
               <Zone>EdsonDell</Zone>
            </DestinationZones>
            <SourceNetworks>
               <Network>WAN</Network>
            </SourceNetworks>
            <DestinationNetworks>
               <Network>Any</Network>
            </DestinationNetworks>
         </NetworkPolicy>
      </FirewallRule>
   </Set>
</Request>

The error it shows me is the following.

<ResponseAPIVersion="1702.1"IPS_CAT_VER="1">
<Login>
<status>Authentication Successful</status>
</Login>
<FirewallRuletransactionid="">
<Statuscode="501">Configuration parameters validation failed.</Status>
<InvalidParams>
<Params>/FirewallRule/SourceZone</Params>
</InvalidParams>
</FirewallRule>
</Response>

Can you do GET on the object and then take that object XML and SET it with no changes?

Can you use WebAdmin to export FirewallRule ?  You should be able to open the tarball and see the XML inside.  Again you should be able to import it back.

Can you do GET on the object and then take that object XML and SET it with no changes?

Can you use WebAdmin to export FirewallRule ?  You should be able to open the tarball and see the XML inside.  Again you should be able to import it back.