SOAP XML request - issue help needed

Hi everyone,
Please help in this issue. Thank you in advance.
I am automating soap request using robot framework, in one test case i am getting error msg as ‘XMLSyntaxError: Start tag expected, ‘<’ not found, line 2, column 1 (, line 2)’.
This error is not due to xml syntax issue.

XML file:
<get: GetfileRequest>
<get: ReturnObject>true</get:ReturnObject>
<get: ReturnMD>false</get:ReturnMD>
<get: ReturnAta>false</get:ReturnAta>
<get: Returnlink>false</get:Returnlink>
</get: GetfileRequest>

after get: i have gave single space purposefully, it is not getting posted otherwise.

My Robot script:
*** Settings ***
Library SeleniumLibrary
Library RequestsLibrary
Library SoapLibrary
Library Collections
Library XML use_lxml=True
Library DateTime
Library String
Library Process
Library OperatingSystem

*** Test Cases ***
Create Soap Client ${getfile_wsdl} ssl_verify=False
${response} Call SOAP Method With XML ${requests_dir}/request_test.xml
${file} Save XML To File ${response} ${response_dir} response_test

Issue is:

In XML file below element value=true (small case) is giving error, Other than true value True, TRUE, False, or false is giving response file. But i have to give small case in my request file then only it will generate correct response file.

same behavior if run this request using soapUi, but in soapui small case true is not giving any error message.

<get: ReturnObject>true</get:ReturnObject>

this attribute value true is giving “XMLSyntaxError: Start tag expected, ‘<’ not found, line 2, column 1 (, line 2)”

KEYWORD ${response} = SoapLibrary . Call SOAP Method With XML ${xml_edited}

|Documentation:|Send an XML file as a request to the SOAP client. The path to the Request XML file is required as argument, the SOAP method is inside the XML file.|