Exclude all folders containing "discarded" with 7z

When I do

7z a test.zip -x!*discarded* test

with

test/test/a.txttest/subfolder/test/subfolder/a.txttest/subfolder/discarded/test/subfolder/discarded/a.txttest/subfolder2/a.txttest/subfolder2/subfolder3/a.txttest/subfolder2/subfolder3/discarded/test/subfolder2/subfolder3/discarded/a.txt

then, unfortunately, everything is still included!

How to exclude every file/folder like */discarded/*? (or, alternatively, exclude any file/folder whose absolute path contains discarded?)

Also, how to exclude all files ending by .txt? (-x!*.txt doesn't work)

I use 7z on Windows.

Note: 7Zip - Command Line : Exclude folder(s) by wildcard pattern? didn't help here.