Apt-cacher-ng + privoxy + flatpak/hub does not work

Hi, I use a sys-apt-cacher-ng, which uses privoxy, i followed this guide for setting this up. I use saltstack to create my qubes. I purposefully deleted my current flatpak vm and used saltstack to create the same qube again. I used Solenes Guide as inspiration when writing my saltstack states. However

export all_proxy=http://127.0.0.1:8082/
flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo

fails if i use sys-apt-cacher-ng with privoxy with this error:

error: Can't load uri https://dl.flathub.org/repo/flathub.flatpakrepo: While fetching https://dl.flathub.org/repo/flathub.flatpakrepo: [56] Failure when receiving data from peer

There are no logs in /var/log/apt-cacher-ng/apt-cacher.log for this call, in /var/log/apt-cacher-ng/apt-cacher.err is only this:

Fri May  9 22:04:09 2025|Detected incoming connection from the TCP socket
Fri May  9 22:04:09 2025|Client name: 127.0.0.1:59224

I tried changing using http instead of https for debugging but then I get this:

error: Can't load uri http://dl.flathub.org/repo/flathub.flatpakrepo: Server returned status 403

this also does not work, but apt-cacher has a log for it in /var/log/apt-cacher-ng/apt-cacher.log: 1746820580|O|679|127.0.0.1|/repo/flathub.flatpakrepo and in /var/log/apt-cacher-ng/apt-cacher.err:

Fri May  9 22:04:49 2025|Detected incoming connection from the TCP socket
Fri May  9 22:04:49 2025|Client name: 127.0.0.1:35280
Fri May  9 22:04:49 2025|Decoded request URI: http://HTTPS///dl.flathub.org/repo/flathub.flatpakrepo

in /var/log/privoxy/logfile is nothing interesting for both calls:

2025-05-09 21:57:55.025 70241006e080 Info: exiting by signal 15 .. bye
2025-05-09 21:57:55.031 745251a8a080 Info: Privoxy version 3.0.34
2025-05-09 21:57:55.031 745251a8a080 Info: Program name: /usr/sbin/privoxy
2025-05-09 21:57:55.031 745251a8a080 Info: Loading filter file: /etc/privoxy/default.filter
2025-05-09 21:57:55.033 745251a8a080 Info: Loading filter file: /etc/privoxy/user.filter
2025-05-09 21:57:55.033 745251a8a080 Info: Loading actions file: /etc/privoxy/match-all.action
2025-05-09 21:57:55.033 745251a8a080 Info: Loading actions file: /etc/privoxy/default.action
2025-05-09 21:57:55.033 745251a8a080 Info: Loading actions file: /etc/privoxy/user.action
2025-05-09 21:57:55.033 745251a8a080 Connect: Initialized 100 socket slots.
2025-05-09 21:57:55.033 745251a8a080 Info: Listening on port 8118 on IP address 127.0.0.1
2025-05-09 21:57:55.033 745251a8a080 Info: Listening on port 8118 on IP address ::1
2025-05-09 21:57:55.033 745251a8a080 Connect: Waiting for the next client connection. Currently active threads: 0

I temporarily removed the cacher config from 50-config-updates and it worked again, so sys-apt-cacher-ng is the real issue here.

After posting this issue i found the solution myself:
Appending the following in acng.conf:
PassThroughPattern: ^dl\.flathub\.org:443$

I should buy a rubber duck