Thanks. It turns out that after updating iOS to 10.2.1 I had to turn off and then on again full access to the TextBlade keyboard in the General/Keyboards settings to make it work again.
So far, any issues I have had with using the TextBlade on Mac, iPhone and iPad have been caused by the Apple software, not the TB. Examples are: bluetooth not reconnecting after the MacBook wakes up from sleeping, bluetooth connection to the TB on my iPhone dropping when I pair my bluetooth earphones, ... things like that. Compared to Apple's sloppy software testing, the TB is a beacon of stability.