Good morning Grisha,
There shouldn't be anything wrong with the servers causing this issue. If you turn debug logging on for your project? This may lead us to a better understanding of what's happening here.
http://devcenter.kinvey.com/ios/guides/troubleshooting#Debugging
Please let me know if you have any other questions,
Grisha Gevorkyan
For the past week I have noticed that my KCSUser.Activeuser() is often getting timeouted, which is quite worrying. By that I mean that after random period of time from 1 hour to 1 day my active user just becomes nil and I get "errorError Domain=KCSServerErrorDomain Code=401 "Invalid credentials. Please retry your request with correct credentials"
Is it some method which causes this or there is something up with servers.