Hi
First check whether you are able to capture the chunked response body value by giving "LB=",RB=" . This will capture the entire rersponse of the page where you can check you are able to capture the values from the entire page or not. If the entire page with the dynamic value is captured and stored in variable, then there might some escape sequence (\) for the special characters to be included to capture the value with the bondary posted.
Also seem the RB is not unique which will not capture exact value.
Regards,
Raghul M
