TaskBar configuration and Microsoft Edge

We are currently customising the Start menu and taskbar using an xml file a GPO. We have no problems with the Start menu, but no matter where we put Microsoft Edge in the taskbar list, it ends up in a different place. According to this Docs page the order of apps in the XML file dictates the order of pinned apps on the taskbar from left to right. Here's what we have configured:

and here is the resulting taskbar setting:

Any help would be greatly appreciated.

Dan