when using vue-cli to build a project, iframe, is used in app.vue but the iframe does not display correctly, but the current page is displayed, that is, the current page is nested on the current page, and the nesting will loop until it crashes:

App.vueurlStartPage.htmlhtml

src=""src="qqq"3

as shown in the figure, if the src is correct, it will render
infinitely. I don"t quite understand