Note that this issue with HTTP pipelining is known to apt upstream, and documented in the apt.conf(5) manpage - this is exactly why the commandline option exists to toggle the behavior, basically.
One setting is provided to control the pipeline depth in cases
where the remote server is not RFC conforming or buggy (such as
Squid 2.0.2). Acquire::http::Pipeline-Depth can be a value from 0
to 5 indicating how many outstanding requests APT should send. A
value of zero MUST be specified if the remote host does not
properly linger on TCP connections - otherwise data corruption will
occur. Hosts which require this are in violation of RFC 2068.
Note that this issue with HTTP pipelining is known to apt upstream, and documented in the apt.conf(5) manpage - this is exactly why the commandline option exists to toggle the behavior, basically.
One setting is provided to control the pipeline depth in cases :http:: Pipeline- Depth can be a value from 0
where the remote server is not RFC conforming or buggy (such as
Squid 2.0.2). Acquire:
to 5 indicating how many outstanding requests APT should send. A
value of zero MUST be specified if the remote host does not
properly linger on TCP connections - otherwise data corruption will
occur. Hosts which require this are in violation of RFC 2068.