What's going on. Why is the @syntax behaving very strangely?

[uselessgoddess]

I have the following parser:

WHITESPACE = _{ " " }
specials = { "\n" }
ref_commons = _{ "(" | ":" | ")" }

reference = @{ ( !ref_commons ~ !specials ~ !WHITESPACE ~ ANY)+ }
point = _{ "(" ~ reference ~ ")" }

values = _{ link* }
value = _{ "(" ~ values ~ ")"}

link = { point | value | real_link | reference }
real_link = _{ "(" ~ id ~ values ~ ")" }
id = { reference ~ ":" }

lines        = ${ top_first ~ ("\n" ~ top_continue)* }
top_first    = _{ link ~ ("\n" ~ children)? }
top_continue = _{ PEEK_ALL ~ link ~ ("\n" ~ children)? }

indentation = _{ ("    ")+ }
children    =  { PEEK_ALL ~ PUSH(indentation) ~ lines ~ DROP }

document = { lines }

But if I write lines = @{ ... } instead of lines = ${ ... }

lines = ${ ... } also is not work

But lines = ${ ... } loses children

How to solve this problem (parse with whitespace without loss of children)?