hey guys, ran also into this problem today. even if this post is 4 years old. the solution you tried, we also came up with and figured out it doesnt work, cause of the same issue.
we used a workaround, that worked for us. iam sure you remember you can setup animation notifies. So make an Notify at the End at the animation.
For a blend it helps like this. For Character as example.
We have an Animation that we wanna automatic stop at its end (Waving Hands). simply create an boolean in character, cast from animbp to character and setup the animation blueprint boolean for your blend. call a function in character where you enable the boolean “isWavingHands” and then call the AnimNotifyEvent from Waving Hands insinde the AnimBp. Get a a reference to character and turn of Boolean “isWavingHands”.
sounds a bit complex, but if you familiar with casting from character to animbp, you should get the trick. otherwise ask. i hope it helps. 
of course iam not sure, if exactly that is your problem.
but we had the issue that we had multie animations, but where not able to get “time remanining ratio” without setting up all animations in animbp manual.