Line 81 of OkapiClient.java is logging verbatim the HTTP response body. The response body has newlines in it, which causes each line to be listed as a separate log line. For example, this call to /loan-policy-storage/loan-policies/ for a production client output over 12,000 lines to the log stream.
Please filter all calls to bodyAsString() to remove newlines before logging. (There are several places in the code of this module where that is happening.)