Screensharing using Anazon Kindle stops the meeting. Is this a licencing issue?

I sometimes tutor my grandchildren and because I live some distance away I do it remotely. I sometimes have to show them a book that is on Kindle but whenever I do so using the screen share option Zoom drops the meeting sometimes straight away, sometimes after a short gap. 

Does anyone know why?

I am using a,Fire 10 inch tablet.