Slow Download from all Proxies Hosted in LXC Containers Only.

[atlas5000]

Hello. This is a lengthy problem so I will condense it to few essential details as possible. I have an lxc container on Proxmox Virtual Environment 8.2.4 using the template for Debian 12 standard 12.2-1 amd64. That container is hosting an http proxy using the application tinyproxy. Applications that connect to the proxy have very fast upload speeds ~300 megabits per second. But the download speed is an abysmal 25 megabits per second. A few important points...

1. I have granted the container the maximum number of cpu cores and unlimited cpu utilization.
2. I have granted the container 512 MB of RAM, which is uses only up to about 15%.
3. While testing download speeds, I notice the CPU seems to barely move past 4%. But during the fast upload speeds it can go up to about 25% utilization.
4. Firewall is disabled for the container.

Here are the steps I have taken to isolate the problem to the container/proxy combination.

1. I installed 2 other proxy applications to see if they would work better, microsocks (socks5) and squid (http). Both show the exact same slow speed of about 25 Mb/s/
2. I installed tinyproxy on the proxmox host and connected to it. The download speeds were an instant ~300 Mb/s.
3. I installed speedtest on the container and ran it. Download speeds were ~300 Mb/s. In other words, download speeds to the container are fine. Only download speeds from the internet -> container-> proxy->my device are slow.
4. I installed a full Debian VM using the debian-12.6.0-amd64-netinst.iso provided on the Debian website. Download speeds crept up to ~300 Mb/s, albeit slower to accelerate than the host test in step 2, but were otherwise perfectly fine.

All tests were done using the same device, which has very high download speeds around ~300 Mb/s when not connected to the proxy in the container.

I have never used containers before and am completely new to Proxmox so I am not sure what logs or other information is appropriate to send. Please let me know whatever you need to assist and I will do my best to provide it.

I appreciate any help you can give! Thank you.