I am from Taiwan. My spoken language is Mandarin and my written language is Traditional Chinese(while the spoken language is Mandarin and the written language is Simplified Chinese in China)
When I purchased letterly a few weeks ago, it correctly transcribed my speaking to Traditional Chinese(I didn't know how it recognized me as a Traditional Chinese user though, maybe from my accent?). I was very amazed and I just loved it.

However, letterly transcribes my speaking to Simplified Chinese now. Even worse, I don't even have an option to translate the simplified text to Traditional Chinese.

I am pretty frustrated and might need to refund the purchase if it's not fixed.