Jenkins 2.263.2: "No Proxy Host" not working

[Christoph Leiter]

Hello *,

my first post here ;-)
We're emigrating from an old Jenkins 1.642.2 to 2.263.2.
The new jenkins was installed and configured from scratch, so no config files or anything else was copied from the old Jenkins to the new one.

"HTTP Proxy Configuration" was done with the same values as on the old one:

Server: <proxyserver.domain>
Port: 1234

Password: secured

No Proxy Host: *.domain.net

A buildjobs uses a "curl" and connects to a host foo.domain.net

This job run on our old Jenkins.

running on the new Jenkins we run into proxy errors. Checking the environment variables before executing the curl showed, that http_proxy was set (whereas it isn't set in the old Jenkins).
The Jenkins-User's environment hasn't set http_proxy.

I found some old issues, which were fixed. Any hints here?
Do we have a wrong understanding of this setting? Bug or feature?

Thanks and regards,

Chris