This is the bug: https://forums.developer.apple.com/forums/thread/729348?answerId=780151022#780151022
It seems that the Network Extension Framework has a bug where combining VPN and Network filters causes deadlocks and timeouts in networking on irregular basis, regardless of the network interface used. This issue happens at a lower level than network interfaces. It can be either a Network Extension Framework bug or a kernel module bug. Given that the network extension frame isn't open source, I can't even debug it, which I would've happily done. Yes, even though I'm not an apple developer, but this bug is so bad that I'm happy to build MacOS components in debug mode and attach a debugger on them when the issue happens... but it's not open source.
So, we have a bug, and we need help from apple devs to fix it... what am I supposed to do? Is there a chance I can get a dev to contact me to debug this together?
What are my options?