[Geoff Bacon]

Thanks Mike

Never used a virtual keyboard before so had to do some research.

Installed and enabled Gboard - no change in behaviour i.e. numeric keyboard appears and disappears (and yes, Gboard is enabled, the keyboard looks slightly different and shows up as Gboard on other edits ie Gboard is working)

To summarize:
The andoid software hasn't been updated 30 Sep 2020
Doing this used to work everytime
I created this thread because it missed the first keypress but then worked on a second press
Updating to 3.8.22 caused it to fail every time
I may have missed a couple of minor updates i.e. probably not 3.8.21 before I installed 3.8.22 

Geoff