Bugs in content types

We have H5P videos embeded (using the latest version of the H5P player) in our custom software.

Randomly while watching the videos the videos stop playing.

This happens on the following devices, operating systems:

Phones, tables, laptops, Chromebooks, and PC's.

Apple, PC, Chrome, and Android.

Chrome, Safari, and Firefox.

I am not a programmer and I'm just wondering how do we trouble shoot this problem?

Thanks for any help/advice.

I have a Wordpress site and added the H5P plugin.

I created a very simple exercise: http://www.ngils.be/schilderijen/

I copy the embed code from the exercise:

Hi,

I just tried the Twitter User Feeds. Whatever username I proved, I get always 

Tweets by ‎@TwitterAPI with tweets retweeted from the Twitter API by @TwitterDev.

See example here