は from what I have been taught is voiced as ha unless it is being used as a particle, where it is voiced as wa.
I have noticed that DuoLingo always voices は as wa.
Was I originally taught wrong or is this an issue with Duolingo?
From my understanding: In words you pronounce it like "ha" (exceptions are konnichiwa and konbanwa), and when it's used as a particle, it's pronounced as "wa" For example：
"haha wa tokei wo kai masu"
母 は 時計 を 買い ます
はは は とけい を かい ます
I was also taught that it was sometimes pronounced wa as a particle and in some words and pronounced ha in other words. I believe that, because Japanese is in beta and because it isn't the most popular language to learn, that they don't have the best of the best working on it and that there will be some bugs in it. I have found about three already; luckily they weren't the biggest mistakes.
If duolingo uses は as わ in other places than particles or words like こんにちは then it's a mistake on duolingo's end
It sounds like they fixed it. It's good to know that they're making improvements.
This happens sometime with ヶ also which is 'KE' but in words like 一ヶ月, it is 'KA'. It just takes exposure to content over and over again. That is why I read NHK Easy everyday.