For me it doesn't work on Chrome android.

As soon as I want to select something and move my finger slightly, the menu disappears, although I am still with my finger on the button

I think I fixed the Android issues, can you give it another try?

Can confirm, it works well in Brave on Android. You do have to tap to initialize the line -- and then tap on the line and drag -- in early examples, but the completed example works well.