The code: https://github.com/mongodb-js/devtools-shared/blob/f1cd6a2276c04ccf82c8f92065ab10f9854e7cce/packages/query-parser/src/stringify.ts#L82 

There are 2 bugs to fix here:

1. v.oid.toString() is always wrapped in single quotes, so any non-string oid round-trips into a string:

• DBRef('col', ObjectId('5e5ea7558d35931a05eafec0')) becomes DBRef('col', '5e5ea7558d35931a05eafec0') an ObjectId becomes a string, which is the common case and will not match the same documents.
• DBRef('col', 1) → DBRef('col', '1')

2. No escaping in collection/db. DBRef("it's", 1) → DBRef('it's', '1'), which is syntactically broken and unparseable. JSON.stringify(v.collection) would handle it (as Code and RegExp already do in the same file).