Hi Rodrigo - thanks for posting.
I went ahead and dug into your new Unbounce page and it looks like the issue you have been experiencing with tiling your background image is actually due to the page sections background images, which are covering up the main background.
You will notice that when editing the page and you click into one of the main page sections to select it, the ‘Properties’ panel on the right of the page will show that the background image has been set to ‘Stretch background to page edges’. Because of this, the white background images of these page sections are actually covering up the main background of your page.
To fix this for your page, you will want to go ahead and de-select the ‘stretch background to page edges’ option for each page section. Once you have done so, you should then be able to use the ‘Page Properties’ panel of your editor to select a background image for your page and tile them as necessary for your design.
I hope this helps to clarify things but if you continue to experience issues with this feature, please don’t hesitate to let us know.
Jacquelyn | Unbounce Customer Success