It’s possible, but not very likely that you have a faulty meter and I know you’ve now updated the testing strips. You could ask Home Health who distribute the Codefree for a control solution/replacement meter.
However, far more likely is that it’s the morning FBG that is often the last to come down. I also started with a very high HbA1c (108/12%) but didn’t test for the first month so have no sense of what happened in that time, but it took at least 6 months of keto to bring that reading anywhere close to normal.
Are you testing before and after meals - how you’re responding to food might give a better idea of the trends in your blood sugars. Alternatively you could get. a 2 week free trial of the Libre to get a fuller picture:
https://sample.freestyle.abbott/gb-en/freestylelibre.html