X squares beside text in epub fixed layout

Good afternoon,

I’m working on epub fixed layout in indesign cc 2018, everything work perfectly, the links, the buttons, the animation..

I’m only facing one problem.. when I try to open the epub in android tablet, there are squares with X appears beside all the text in the page like the images below:

Untitled 2.png

Untitled.png

1.png

I applied paragraph and character styles it worked for awhile but the problem happened again and I have no idea why.. I watched Lynda courses, and I did searches in google they said Microsoft have issues with fonts in windows 10, so I used default fonts but the problem still occurred. I choose Show Hidden Character and delete extra spaces and characters, but nothing change..

The file worked perfectly in iPad (iBooks), but it didn’t work in Samsung tablet…
I’m using Infinity Reader app to open the file as the buttons worked in this app only..

I hope to find the solution here.

Thank you.