Freeze in state :[XCUITEST] Waiting for WebDriverAgent server to finish loading

Appium 1.6.0 , Xcode 8.1, iOS on real device 10.1

After 5-6 test runs (i ran only one test) the WebDriverAgent seems to be stucked in a weird state. The only thing that I can do here is to restart the phone. Not a viable solution. Any thoughts?

Here are the logs:
server_logs.txt (22.4 KB)

Also anyway to make the test faster? In UIAutomation this test took about 60 seconds, now with the XCUITest driver it takes about 250 seconds!