As a part of Forge Data Management API performance initiative, the Forge team is planning to disable request/response buffering at Forge API proxy layer. If you are sending POST or PUT request without the required Content-Length header information. The Forge proxy will reject the call starting end of February. The first API affected by this change is the OSS PUT objects and OSS PUT resumable requests, but all POST/PUT requests might be affected.
Usually most of the SDK and REST client add this header automatically, but it would be a good idea for you to verify you are following REST programming best practices and provide that header to the request. The Forge team already have directly contacted people having this issue, so if you have not received an email from us, it probably means you won't be affected.
Our current plan is to disable request/response buffering by end of February.