Dictation intermittent Kindle HD fire 10

Tablet is Kindle HD fire 10. Both Alexa and dictation in general worked very well for many months . But a month ago it stopped working. I was unable to find any information that help me . The only thing I thought that might have changed about a month ago was that I installed AVG antivirus . About a week ago dictation worked again . Based on what I had read I thought that maybe it would be a keyboard setting that would affect dictation for the better. When I look at choosing a keyboard , I saw Japanese keyboard is highlighted but the button is off , and the US keyboard choice was desensitized. I did change the keyboard from dark to light . But who knows what other changes I may have made - it just started working again, until the next day when it stopped working. Is working now and I have dictated this question ; so don't be surprised if there are typos and grammar mistakes .

 Does anyone have a definitive explanation as to how I can turn on or off dictation capability ? I believe I was able to dictate by hitting the microphone on the keyboard before I downloaded Alexa . After uninstalling AVG I installed malware bites. Maybe that last action helped?

 My criteria for success understanding the problem is to be able to turn dictation off for the day and then turning on the next day and have it work for two weeks .