SwiftUI image has isAccessibilityElement == false

My SwiftUI app uses an Image with a tap gesture:

Image(systemName: "xmark.circle.fill")
    .accessibilityIdentifier(kTextFieldClearButton)
    .foregroundColor(.secondary)
    .padding(.trailing, 6)
    .onTapGesture {
        dataSource.textFieldText = ""
    }

In a UI test, I want to tap this image to execute its action:

let clearButton = app.images[kTextFieldClearButton]
clearButton.tap()

However the action is not executed.

I then set a breakpoint at clearButton.tap(), to execute lldb commands. Here are the results:

(lldb) p clearButton.isHittable
    t =   439.54s Find the "TextFieldClearButton" Imag
(Bool) true
e  

It is a little strange that "Image" has been interrupted by (Bool) true, but the image is hittable.

p clearButton.isAccessibilityElement

gives

(lldb) p clearButton.isAccessibilityElement
(Bool) false

I don't understand why this Image is no accessibility element. I thought, SwiftUI Views are by default accessible.
What can I do to make it accessible so that clearButton.tap() works as expected?