Can't echo close parenthesis only when piping

I have a pretty peculiar problem, echo writes "ECHO is on." even if it has an argument, but only when printing to a pipe, for certain arguments.

My use case is I'm writing a script file to feed into an interpreter. On Linux I use heredocs to achieve this very nicely.

prog arg1 - arg3 arg4 \
<< EOM
    start server load (
        foreground
        initial database '$database'
        directory $directory
        from file '${database}.ext'
    );
EOM

---

For Windows' batch I recently discovered something very similar;

(
    echo start server load ^(
    echo     foreground
    echo     initial database '%%d'
    echo     directory %directory%
    echo     from file '%%d.ext'
    echo ^);
    echo.
) | prog arg1 - arg3 arg4

But I kept getting the following error:

E7511-ACE: '-' line 6: An error has occurred while processing the DDM file.
Caused by
E2420-ACE: Expected punctuation character ')'.
4:     directory 'C:\Users\redacted\AppData\Local\Temp'
5:     from file 'testing.ext'
6: ECHO is on.
---^---
7:  )

---

But if I instead, begrudgingly, use a temporary file, it all runs fine!

(
    echo start server load ^(
    echo     foreground
    echo     initial database '%%d'
    echo     directory %directory%
    echo     from file '%%d.ext'
    echo ^);
    echo.
) > tmp.txt
prog arg1 tmp.txt arg3 arg4

Contents of tmp.txt;

start server load (
    foreground
    initial database 'testing'
    directory 'C:\Users\redacted\AppData\Local\Temp'
    from file 'testing.ext'
);

---

I even tried mocking up a .bat to try and show this but all it did was make me think I am crazy

@echo off
set databases=a
for %%d in (%databases%) do (
    (
        echo bob ^(
        echo     %%d
        echo ^);
    )
)
pause

output:

bob (
    a
);
Press any key to continue . . .

I don't know any .exes that accept stdin and just write it out to the screen/to a file for me to test my 'it's broken when piping' hypothesis (Windows' type & echo are less versatile than Linux' cat & echo),

do you guys have any ideas?