Opens to black screen; cursor/entry update sometimes delayed (Android)

Using Gforth on Android in the last few days, when starting Gforth I see a black screen with only the on-screen keyboard displayed. Toggling the keyboard or typing usually makes the text appear.

Also, when moving the cursor, the cursor frequently stays where it is until another key is pressed.

Rarely, when typing, 1 or 2 typed characters will not appear until another is typed.

Devices & OSs:
Samsung SM-P615, Android 13
Samsung SM-A405FN/DS, Android 11