Maybe related to :
I can reproduce this behaviour by using the following method:
- Open any app that requires numeric input and provides a numeric keyboard for it (e.g. lelig:mmHg)
- Switch to landscape mode
- Close the app in landscape mode while the numeric keyboard is displayed.
Now every input field in every app just opens a numeric keyboard.
To restore the correct keyboard layout for the respective input field, proceed as follows:
- Open any app that requires numeric input and provides a numeric keyboard for it (e.g. lelig:mmHg)
- Switch to portrait mode
- Close the app in portrait mode while the numeric keyboard is displayed.
Now you have your alphanumeric keyboard back.
Tested on Xperia X (F5121) Suomenlinna v4.3.0.12 with app lelig:mmHg and my own little converter app