garbled characters in Calc

Hello, I am on LibreOfficeVersion: 5.1.6.2
Build ID: 1:5.1.6~rc2-0ubuntu1~xenial3
CPU Threads: 8; OS Version: Linux 4.13; UI Render: default;
Locale: en-US (en_US.UTF-8); Calc: group. *
When I type characters in a cell in Calc, it shows garbled view of characters. They become readable only after I hit Enter. How we can fix it?
thanks!

“garbled” exactly means what?

Is the “language” setting of your keyboard the same as the “locale” setting for your version of LO? (en-US UTF-8).(We have problems similar to what you describe when my wife, who is bilingual, uses the Can-French keyboard setting.)