502 Bad Gateway gravitee

Question

I keep getting 502 Bad Gateway when my angular client trying to call my api rest endpoint. This request is a POST with a large body arround 15Mo or more. Usually my gravitee gateway is tracing these calls , but this one is not (all big request bodies, their response are the same 502 bad gateway and not being traced on it). So I'm trying to understand the situation here, the most probable thing that could be the case , is that gravitee trying to trace this request , but while is the body is too big he can't, so client request is down !
Kindly suggest is there any solution to this issue, cause my request doesn't reach my backend endpoint treatment and I tried to add some headers (content-length, request-limit-size) to my client http request, adding timeout, retry calls more than once but nothing works for now !