Investigation: you have to type into crosswords slowly on Android

From a user comment

> you have to type unnaturally slowly in order for it to input the letters correctly

This is presumably due to the way the Android keyboard works.

[Possibly related](https://www.theguardian.com/crosswords/cryptic/29646#comment-171030489):

> the new design is unusable on an Android phone with Firefox as the on screen keyboard disappears after each letter is entered.

Start by reproducing the slow-entry behavior on an Android phone, including the related case where Firefox's keyboard disappears after each letter. The issue names no files, tests, or entry points; done would require identifying the cause and defining a verified fix for reliable letter input.

Written by the indexing model from the issue text.