Disappearing speaker

Simple Past 2. Lesson 11: Ver : Question 9 of 12.
The video of the Portuguese speaker disappears into a white background after speaking once. I have noticed this happened once before in another unit but did not report it.

Hi David,
I think this is something not related with the particular question but more with Android. I’ve tried to reproduce the issue on my Android (version 8) but it all worked well. Unfortunately I can do much here. Yet, let me know if this start happen more often.
Thank you.