A clue for why angular9 demo in examples folder failed in some cases

[sylvenia]

I mean

• try yarn start:angular9 ahead in another terminal
• then start the main project yarn start:main or just yarn examples:start

compiling and serving angular micro project before main project started solved my problem.

maybe the reason is the angular project failed compiling or something in parallel serving when yarn examples:start?
(just some guess, I am not familar with angular compiling)