This is happening because your *.gsp paths are being handled by GroovyPagesServlet. To fix it, you need to remove GroovyPagesServlet.:

• Instead, create a mock servlet class

package stackoverflow

class GroovyPagesServletMock {
}

• Then register it in resources.groovy

import stackoverflow.GroovyPagesServletMock

// Place your Spring DSL code here
beans = {
    groovyPagesServlet(GroovyPagesServletMock)
}

I got it working this way. Hope this helps!

enter image description here

Sample https://github.com/mkmikael/stackoverflow79641438