This happen with your phone?
When we typing letter 'b' (in contact search, sms, note or other) with pressing Numpad '2' for twice. It will have some change (about 5-10%) come out with letter 'c'
This is happen on all second or third letter when typing (example letter 'e', 'h', 'k'...)
Tested in Software version: 13.00.17.01