Unity Asset XmlLayout losing track of its xsd

I'm using the excellent asset XmlLayout. Often when I'm editing the XML docs it seems Rider loses track of some parts of the XmlLayout XSD. 

Several hours ago, when I started work, XML Intellisense was working just fine. Now I'm seeing errors like below.

I have not yet hit on a surefire method of restoring the appropriate behavior. Sometimes restarting rider works, sometimes changing the xsi line and then correcting it fixes it. Sometimes I just have to live with it until such time as it decides to work again.


I believe this is a Rider problem as I can open the file in VSCode and all the Intellisense behaves exactly as it should.