Web-Proxy Problems / Impossible to Update Opensuse

Hi together,
after more than 1 year who work´s all like a charm, but today i have problems to download Update-Packages for my Opensuse-Tumbleweed-Client behind the IPFire 2.27 (x86_64) - core174.

error: transaction-end-before-headers

Oh and actually now, after i try with follow the link of the web-site: Package repositories - openSUSE Wiki to /tumbleweed/repo/non-oss - openSUSE Download i get the message: Zero Sized Reply

And of course, it´s the same machine who i try write this letter.
TRY means, i could save a draft with only one line of the this topic but i could´nt publish within.
As i cut off the IP-Fire machine and use the pure connection with my fritzbox i could publish.

What´s wrong with my configuration ?

Thanks for any answer !!

UPDATE: AND NOW - WHAT SHOULD i say: My Opensuse-Update work´s again. But only with the command: zypper up _ and not zypper dup

But not to save the edit of this topic. → error: transaction-end-before-headers