The Mitosis and Meiosis exercises do not show up on any device, no matter version or browser.
The Form 4 Human Biology content was taken directly from the Khan Academy channel on Studio.
As for PLIX content, it is only the older iOS 9.3.5 that is not working. This has happened before with HTML5 books such as African Storybook content on this older iOS platform. BTW, doesn’t matter which browser one uses on iOS because all browsers are requiredby Apple to use the builtin iOS webkit as their engine. As I’m typing this to you, the PLIX book “Temperature Transitions” is in a loop of trying to load, giving error “A problem occured with this webpage so it was reloaded,” then trying again. It finally failed with "A problem repeated occured on… lengthy URL.
Here’s the details of our Kolibri system: Version: 0.13.2
Installer: kolibri(apt) with kolibri-server Version: 0.3.8~beta2-0ubuntu1
Device name: raspberrypi
Free disk space: 56 GB
Server time: Fri May 29 2020 19:50:47 GMT+0100 (WAT)
Server timezone: Africa/Douala