Problems to connect DF with remote service


I have this problem with DF version 2.9

I connect DF with a remote service. If I call a this remote service the response time is 400-500ms. Then, If i call the service from DF, the response become in 6s.

The service is a call to DB and in the response bring back a base64 image. If the image isless than 7kb It works fine, the TTL is the same, DF takes 400-500ms but if the image is bigger than 7kb, DF takes 6s.
Calling directly with curl to the service It works fine.