I faced this issue when I was using the UXPin desktop app on my mac. I don't see this issue on the browser-based app.
@Luka Filipovic92 I have tried now and not seeing any issues at my end. Hope this helps. I just tried with 2 boxes.
https://preview.uxpin.com/47bdcfa7afc6cc8d89ee8ea8a92bce982201614d#/pages/134942835?mode=cvhidm83