nushell: `cp` cannot find source file in the `cd`ed directory in script

Describe the bug

def main [stem: string] {
    let in_dir = $env.PWD

    cd '~/Templates/dev'
    # let template = ^ls -1
    #     | sk -i --ansi -c 'fd {}' --preview 'bat -pp --color=always {}'
    #     | str trim -r
    let template = 'foo.rs'

    echo $template

    let extension = $template | path parse | get extension
    let dest = $in_dir | path join $"($stem).($extension)"

    cp $template $dest
}

This is a script to copy my template file to the specified location. I’m sure that the file $template exists. But I got an $template not found error when running the script.

Strangely, it works fine under interactive mode via typing line by line.

How to reproduce

# 1.
$ mkdir -p ~/Templates/dev

# 2.
$ touch ~/Templates/dev/foo.rs

# 3.
$ script bar

Then you will get an file not found error.

Expected behavior

It should create an file named bar.rs with the content of foo.rs in the current directory.

Screenshots

Configuration

key	value
version	0.86.1
branch	makepkg
commit_hash	cb754befe91d6ba3e853004fe90ff3a1af7caa9b
build_os	linux-x86_64
build_target	x86_64-unknown-linux-gnu
rust_version	rustc 1.75.0-nightly (1c05d50c8 2023-10-21)
cargo_version	cargo 1.75.0-nightly (8eb8acbb1 2023-10-17)
build_time	2023-10-24 21:55:19 +00:00
build_rust_channel	release
allocator	mimalloc
features	default, sqlite, trash, which, zip
installed_plugins

Additional context

No response