Apk download problem

Good morning
when I test my app with companion, everything works very well, and when I download my app on my smartphone I only have the title and the rest is white???

Try to reload the website

no nothing has changed, still the title and everything else white, yet in test it works very well

I think I found it’s “Cardview” which does not want to open, but I don’t know why, yet it is clearly visible

You have to share your blocks or aia…
Provide some screenshots

I deleted “Cardview” and then I put it back with my elements inside and it works. thank you