Cypress - How to switch between elements in iframe

I'm trying to interact with some elements inside an iframe with cypress. If I use the approach in https://bparkerproductions.com/how-to-interact-with-iframes-using-cypress-io/ for only one element per test, everything is fine.

# commands.js
Cypress.Commands.add(
    'iframe',
    { prevSubject: 'element' },
    ($iframe) => {
        return new Cypress.Promise(resolve => {
            $iframe.on('load', () => {
                resolve($iframe.contents().find('body'))
            })
        })
    })


# landing_page.spec.js    
cy.get('iframe').iframe().find('#happybutton').should('be.visible')

However, I want to look for multiple elements, click on them, and check if they are rendered correctly, but if I assign the iframe contents to a variable and reuse it to locate another element (for example, a button), cypress tries to locate the second element (for example, a menu) from the first element (the button, which is doomed to fail, because the button does not contain the menu).

# landing_page.spec.js  
let iframeContent = cy.get('iframe').iframe()
iframeContent.find('#happybutton').should('be.visible')
iframeContent.find('#myMenu').should('be.visible')

I tried using different variables, or calling directly cy.get('iframe').iframe(), every time I wanted to interact with different elements, but cypress gets trapped in an infinite loop and the test never ends (but no errors or warnings are produced).

Does anybody knows a way to avoid this infinite loop? As I want to reproduce a sequence of steps to build a test case, it is not possible to isolate each interaction in a different test.

Or does anybody knows of a framework that is more suitable for working with iframes?