I guess i figured out why.
In Hugo 0.55 we changed how the % delimiter works. Shortcodes using the % as the outer-most delimiter will now be fully rendered when sent to the content renderer (e.g. Blackfriday for Markdown), meaning they can be part of the generated table of contents, footnotes, etc.
The above description only applies to those shortcodes with included content directly in related html file.
But for those like having
readFile command, the file content to be read is not fully rendered before sent to the markdown processor ( goldmark in my case).
So I have to write a pre-process script in Python to replace
include direction with real file content.
Really hope Hugo guys could solve it in better way.