XHProf Ajax method on SoapClient. Why so slowly and where to dig further?

Question

Zend Framework

Where to move on, to find the causes of anomalies in the work of PHP, if everything converges on SoapClient'e?
In our project with ZF2 front and ZF2 back (the current terminology for distinguishing APIs at the front and core),
there is a method for autocompleting cities / hotels. This is one of dozens of AJAX-methods, throwing out "cold" anomalous tricks, such as 25 seconds. waiting for a request at 0.7 (if SOAPui is knocked on one thread) to the kernel.
SOAPui test:

And here is what profiling a request from the front looks like, with anomalous system behavior: