[Meta] Big Pipe related issues, causing seemingly random failures

Problem/Motivation

This issue is intended as a resource, listing Big Pipe related issues, causing seemingly random failures, affecting contrib modules and Drupal core.

Inspired by 🌱 [meta] Known intermittent, random, and environment-specific test failures Active , Big Pipe can sometimes cause mysterious bugs, like certain JavaScripts not loading, or loading in the wrong order. It can be difficult to pinpoint the problem, so perhaps a [meta] issue collecting them can become a resource, and help users looking for a cause and solution?

Steps to reproduce

See a bug, spend some time understanding it, realize it is Big Pipe related.

Proposed resolution

Collect issues, and expand this issue with descriptions of different scenarios, and solutions, to become a resource and help, guiding users to faster understand the cause, and solution to their problem.

Maybe creating a "How Big Pipe can cause mysterious bugs" documentation page in the style of How to fix "The following module is missing from the file system..." warning messages → is better?

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet