Sync gateway Changes Feed Very, Very Slow

I am developing an app using locally installed sync gateway 2.0.0 and couchbase server 5.1
So my bucket size is relatively small , I got 5800 items in my bucket (this is just a test data).

But when I call sync gateway _changes feed it sometimes takes very long time, on mobile device I got SocketTimeout exception.

Sometimes it takes 95 - 100 seconds to COMPLETE!!!

I am using URL:
http://127.0.0.1:4985/.../_changes?style=all_docs&active_only=true

Please tell me how to increase perfomance, may be I should configure Sync Gateway somehow?

UPDATE: Found out that it happends when I add new documents to sync gateaway. What is the reason? Does it process new changes so slow or what? How to resolve this?

@Nikolay_Nikolaev, it should not take that long. Is it possible for you to try sync gateway 2.7.0 as performance is much better in 2.7.0. Let us know if you see same issue with sync gateway 2.7.0