I’m quadriparetic, and voice control of my television was amazing when I first got it through SmartThings/Harmony/echo back in August 2015. But by November 2015 it had broken two or three times because of changes that smartthings made and it just became very frustrating.
Once harmony introduced their own skill (the original “Red” one), I switched to that, and it was much more stable. Then they introduced a newer “blue” skill, which added more features. All good. The only problem is that it can only work with one harmony hub. If you have two, you can use the blue skill with one and the red skill with the other, but that can be confusing because the control phrases are different. But if you just have one Logitech Harmony home hub and you just want echo control of it, I highly recommend the blue skill.
If you have more than two Harmony hubs and you want echo control, the best thing I found is yonomi, which does have official integrations with both harmony and echo. This is a free app. It’s not perfect: there’s no integration with SmartThings, and all of the activities from all of your harmony devices show up in one long list, but it does work and is quite quick to set up.
So if you have someone who is physically dependent on voice and they don’t want to wait for smartthings to fix the integration, you could use one of these methods.
In the meantime, definitely report the problem to support, as it is an official integration. I expect that smartthings will fix it sooner or later, but then I expect it will also break again eventually, as they just don’t seem to test this before releasing new features.