Description:
Use SAL_USE_VCLPLUGIN=kde5 to launch LibreOffice 6.2 rc2, I can input both English and Chinese but can not delete characters with Backspace.  I have to select the characters I want to delete and then hit Backspace.

Backspace works well under SAL_USE_VCLPLUGIN=kde4.  It also works well in Writer/Impress/Draw/Math under SAL_USE_VCLPLUGIN=kde5.  Only Calc under kde5 has this problem.

Steps to Reproduce:
1. open Calc with SAL_USE_VCLPLUGIN=kde5
2. Input some alphanumeric in a cell
3. Use Backspace to delete

Actual Results:
Backspace doesn't work.  No any reaction.

Expected Results:
It should be able to delete characters.


Reproducible: Always


User Profile Reset: No



Additional Info:
When I select some texts I can use Backspace to delete.