Web service proxy server in Karaf with Camel and cxf adds 1000 to MTOM messages - web-services

Question

I am creating new proxy for web services in Karaf 4.4.1 with Camel 3.18.1 and cxf 3.5.3.(I've tried it on older versions too 4.4.0, 3.18.0, 3.5.2). And it works fine, but I have a problem with MTOM attachments. For some reason it adds several times number 1000 into the message. And it is not every 1000 bytes. The spaces between them are different (from 377 to 4157 bytes). Here is picture of comparison of my incoming messages. The bad one goes through proxy and the good one don't:
comparsion 1
comparsion 2
Does anyone knows where is the mistake?
Here is my blueprint:
...
<camelcxf:cxfEndpoint id="SrvEndpoint">
<camelcxf:properties>
<entry key="dataFormat" value="CXF_MESSAGE" />
<entry key="ws-security.ut.no-callbacks" value="true"/>
<entry key="ws-security.validate.token" value="false"/>
<entry key="schema-validation-enabled" value="true" />
<entry key="lazyStartProducer" value="true" />
<entry key="mtom-enabled" value="true" />
</camelcxf:properties>
<camelcxf:inInterceptors>
<ref component-id="SrvWsSecInterceptor" />
<ref component-id="SrvAuthenticationInterceptor"/>
<ref component-id="SrvLoggingInInterceptor"/>
</camelcxf:inInterceptors>
<camelcxf:outInterceptors>
<ref component-id="SrvLoggingOutInterceptor"/>
</camelcxf:outInterceptors>
</camelcxf:cxfEndpoint>
<!-- this is the Camel route which proxies the real web service and forwards SOAP requests to it -->
<camelContext id="SrvRoute" trace="false" xmlns="http://camel.apache.org/schema/blueprint">
<route>
<!-- CXF consumer using CXF_MESSAGE format -->
<from uri="cxf:bean:SrvEndpoint"/>
<!-- Need to remove the http headers which could confuse the http endpoint -->
<removeHeaders pattern="CamelHttp*"/>
<!-- Don't know why but if not set returns empty response header and body -->
<setProperty name="CamelCXFDataFormat"><constant>PAYLOAD</constant></setProperty>
<!-- send proxied request to real web service -->
<to uri="{{SrvProxy.target.url}}?throwExceptionOnFailure=false"/>
</route>
</camelContext>
I've tried to change dataFormat to PAYLOAD and clean it from authentication and validation but nothing helped.