How to disable network cache?

Question

Node.js

Yes:
Ubuntu Server 20.04
NodeJS server with heavy/slow incoming traffic processing tasks.
Problem:
The client makes a constant upload of traffic to the server, after the client has disconnected the server / application still continues to receive data from the client and considers it connected for a few more minutes. As I understand it, the data from the client first gets into some kind of cache and from there it is loaded into the application. It is necessary that they do not reload, stop receiving data upon disconnecting the client. Where to look for this cache and how to disable it?
As tried to solve:
Exposed on all sockets setNoDelay. It helped with the download from the server, but not with the upload to the server.