On Windows and MacOS, `source()`ed packages do not show function suggestion even Namespaces attached and loaded

[Fred-Wu]

I am working on Windows 10 and using the native R terminal for my work projects. I have a script to setup some configurations and packages, and source() it from other scripts.

However, auto-suggestion on functions do not work if loading packages using this way for the first time even Namespaces are attached and loaded.

Also tested on my own MacBook, it happens too.

For data.table

For haven

However, it only works after I open 0_loadLibrary.R

And then as soon as I close 0_loadLibrary.R, it stops working again.