Traffic Split not getting saved from console UI or CLI

[Vikram Chandna]

I am trying to make a version of deployment as default from console UI. 

The operation is successful. See first image.

But when I do refresh, i see settings getting cleared off. See second image.

Is this a bug?

I tried through command line also as..

gcloud app services set-traffic --splits <version>=1

command returns no error, but i dont see desired version getting 100% of the traffic.

Any guidance on this?

I am using node.js which is on flexible env. Is this because of that?

App was deployed using gcloud app deploy command. Its a simple hello world app taken from online documentation.