Thank you for your post and for your feedback about the IDE.
This is known issue for us.
Our developers are going to fix this as soon as possible.
Currently, as a workaround, you can do the next: please open the Main Menu -> Tools -> Options -> Text Editor -> Code Assistance, and remove all the symbols from the 'Commit Completion by typing following characters' list. In addition, you can disable the 'Preselect Completion in Competition List' option that is present in the same settings menu.
I kindly ask you to inform us if this workaround works for you.
I'll keep you updated when the issue will be solved.