The control characters do not work after a system reinstall

[Kaj Persson]

After a reinstall of Debian (ver. 9) and GNUCash the control characters 
do not work in GNUCash. Common characters (like letters, figures etc.) 
behave normally when I write them in a field, but when I need a control 
character (e.g. backspace, home, delete) nothing happens. The cursor 
does not move and the character is unaffected. However when using TAB 
and shift+TAB it behaves normally and the cursor moves to the next (or 
previous) field. I can position the cursor as usual with a mouse click, 
but nothing happens when I try to edit the text with a control character 
at the chosen position. Inserting text ia however working fine. And this 
is true for all fields of a transaction. The date field can be edited 
normally via the characters +, -, m etc.

Other programmes (emacs, gramps, thunderbird et al) behave normally and 
there all the control characters act as expected.

Any suggestion, anyone?

Regards
Kaj Persson