I’ve been reading various forum posts and trying various options as this worked without any problem on our Fire TV Stick.
I’ve switched HDMI cables, tried a different HDMI port on the television and that didn’t make a difference.
I restarted the Fire TV and then there was an update available. Installed the update but that didn’t seem to make a difference either.
Until now I was focused on Bosch as that was the show I was watching on the Stick and on my phone.
I looked at the list of other described programming available on Amazon. I looked more for the shows or movies that are free with Prime as I wasn’t ready to spend any money yet, trying to get this working.
After having Alexa find the title I was looking at online, I noticed none of these had Ultra HD next to them on the Fire TV as Bosch did.
I played these movies, no problem at all selecting English Described in the menu during playback. I tried about four and all worked fine as they are supposed to. Just for kicks I decided to give Bosch another try.
I had Alexa find Bosch and this time the Ultra HD was missing on the Fire TV.
I played an episode and now the English Described was there in the menus as it was supposed to be and as it was in the other movies and shows I just had success with.
I’ve gone back into the regular menus and then back to watching Bosch and the Ultra HD was still gone and I can still access the setting for English Described during playback.
This seems to be some sort of a bug I encountered in Fire TV. I’m not sure what got me out of the bug, restarting & updating, restarting a few more times or maybe watching the other content that wasn’t marked as Ultra HD.
One thing I know for sure, the person my Wife spoke with at Amazon Disability Support was 100% wrong that we need a 4K television to get the English Described audio setting with the Fire TV.
Also unless you know that your tv / AV receiver etc.. setup supports Dolby Digital Plus, its best to turn that off in the Display & Audio settings of the Fire Tv.