Image Hotspots: Scaling down plus sign

One of my students reported that on her mobile device the plus sign of an Image Hotspots prevented her to make the exercise (it didn't scale, hiding the words, so she couldn't see where to tab).

This is the page: https://sandbox.ital2.org/risorse/competenze/lessico/lultima-parola-al-m... (first activity: "1. Per cominciare…"). Attached, is the screenshot she sent me.

Moreover she reported me a problem (an old one I already knew) with Drag The Words. On her (and also mine) phone, it's impossible to drag words.

Here is an example page: https://sandbox.ital2.org/risorse/competenze/lessico/cantierando/ (second activity: "2. In equilibrio sui ponteggi").

Thanks for your attention.