Thank you Chuck. I figured out the cause, and a new build with a fix
is coming shortly.

For anyone interested in the background, it appears that we are
running at the very limit of the tight memory allowance for iOS
keyboards. Some recent change made us cross the memory threshold ever
so slightly on some rare occasions, and iOS simply restarts the
keyboard whenever that happens.

The real fix for this is a complete rewrite of the word recognition
engine, something which is planned for the future and is an area I am
particularly excited about. But there is a lot of work before we get
there, so don't hold your breath just yet, smile.

Kosta