In the Memrise app, the Tibetan characters are messed up

In the Memrise app, as a person types Tibetan characters (by touching the characters provided by the app), the super-script and sub-script parts of the characters are pulled to the right, destroying the characters and making it impossible to see what one has previously typed. This doesn’t happen when you use Memrise in a web browser. Works fine in the browser. Also, the browser lets me use the Tibetan keyboard which is much easier (after you get used to it).

I am using an iPad, 9th Gen. I have an old iPad mini2 and it doesn’t work there, either.

Please fix. Thanks!