Deleted, last answer by topic starter is more informative description of that problem persists.

I created TSI number 754458218 and specified more examples of apps that are broken by this scheme.

Just installed 11.1 RC and the bug was still not fixed. :( So disappointing. Will we need to keep our "Big Sur workarounds HOWTO" for at least one release?

Hello! Are there any updates?

Hello! It is very important that SSH should be connected while no transparent network extensions are running in the system. Then I start network extension and just press a key in SSH, and voila: It is also reproduced with node.js with SSL. If I run the following code with link to large file: https = require('https') https.get('link_to_large_file'); And then start transparent proxy network extension, and in minute node.js will eat CPU too.

I actually already created the feedback: FB9125326 Also added information how to reproduce bug using "node.js" to it.

The interesting thing is that a more recent version of OpenSSH has a fix that properly detect this unexpected behavior Eventually, Apple SSH and libuv (nodejs) may adopt to this behaviour too... But it will not be an ideal solution, socket continues to behave in a way that usual socket doesn't, and there are may be other apps that doesn't expect this. :(

On Big Sur 12 beta 2 and 11.5 beta 4 issue is still reproducible with node.js. Almost all Electron apps including Signal messenger are affected. :(