variant: AHT20 # Specify the model as AHT20
Silly thing to miss - Thanks mataksik - took me 5 AHT20 BMP20 cards to discover they were all good 
this one solved my problem. thank you very much
also double checked and it is an aht10 but only works when you set variant to aht20
Thank you for this post. This was my problem also!
Kept getting the “Communication with AHT10 failed!” and “Component aht10.sensor is marked FAILED” error messages, but it showed an address of 0x38 which meant it was communicating. As per your post, changing to “variant: AHT20” did the trick.
It seems like i see a lot of people have issues with this sensor. Its much more common than posts with dht or dallas type IMO. Quick little google search might sway decisions and choose one with less problems. I guess its just easier to be a follower than a leader?