How to properly configure SOAP client to work with Unistream API?

Question

PHP

Has anyone experienced integration with this service? The problem is that the interaction goes fine only until the function is called directly. Wireshark shows that WSDL is being received, XSD schemas are being requested and received, then xml is sent directly with a call to the desired function, and then in the case of PHP SoapClient, it’s just silence, if it’s a python soap client, then error 400, if soapui, then timeout. There is nowhere to make a mistake, soapui and python themselves generate a data structure using wsdl, it remains only to substitute the authentication data.
The certificate is also indicated, but the support reports that if there was a problem with the certificate, the service would return a specific error about the signature.
Has anyone encountered this problem and solved it?