I have the same issue as well. I got my b char typed double, but it is not always. Somehow if I try to focus on typing the sentence the b is not double. But when I just type as usual it will be keep in double.
Here I am trying to type:
'''bb''' b b b b b b b b b b '''bb''' b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b '''bb''' b b b b b b b b b b b b b b b b b
So as you can see the double b typed 3 times.