GnuTLS connection get slow and fragmented

Description of problem:

I have spend time with Debian apt devs because i was facing very slow installation of anything and after investigation we have reached that the issue is with gnutls. we have used as well different tls library like openssl and we have tested the outcome and found that its working fine with openssl so there is a problem with gnutls.

The test is simple:

apt and wget relying on gnutls while curl relying on openssl, here is the outcome:

for apt (test to install chromium + debian repository with tls):https://pastebin.com/xuJ2wR6d

wget vs curl: https://pastebin.com/D66HHzp9

(My downloading speed can reach 10MB~ per second)

tcpdump of wget: https://pastebin.com/iMYFDX4a

So its either there is a bug within gnutls when its used inside debian or there is a bug within gnutls that the ISP is using it to smash the connection whenever see it or smashing it without any bug...etc

if you have commands or so to investigate i would be happy to help figure this out.

Version of gnutls used:

gnutls 3.6.7-4 and 3.6.14-2

Distributor of gnutls (e.g., Ubuntu, Fedora, RHEL)

Debian 10 and 11

How reproducible:

Live in a restrictive regime