The MongoOptionsExtension copy constructor (MongoOptionsExtension(MongoOptionsExtension copyFrom)) copies most configuration fields (ConnectionString, ClientSettings, MongoClient, DatabaseName, CryptProvider, CryptProviderPath, KeyVaultNamespace, KmsProviders, QueryMode) but omits two: CryptExtraOptions and QueryableEncryptionSchemaMode.

Because every With* method clones via this copy constructor, chaining any With* call after one that set those fields silently loses them.

Repro

var ext = new MongoOptionsExtension()
    .WithCryptProvider(provider, extraOptions: someExtraOptions)  // sets CryptExtraOptions
    .WithQueryMode(MongoQueryMode.DriverLinq);                    // clones via copy ctor -> CryptExtraOptions LOST
// ext.CryptExtraOptions is now null

Same for QueryableEncryptionSchemaMode set via WithQueryableEncryptionSchemaMode(...) followed by any other With*.

Impact

Silent loss of Queryable Encryption configuration (extra crypt options + schema mode) depending on the order of fluent option calls — a data-fidelity / config-correctness bug in the encryption surface.

Fix

• Add CryptExtraOptions = copyFrom.CryptExtraOptions; and QueryableEncryptionSchemaMode = copyFrom.QueryableEncryptionSchemaMode; to the copy constructor.
• Add a clone-fidelity round-trip test asserting that every field survives an arbitrary chain of With* calls (guards against future omissions).

Notes

• Pre-existing — the omission exists on main and predates the native-query work (EF-322/EF-323/EF-329/EF-331). Found during the EF-331 code review. Should be fixed on its own branch off main, not folded into the native-query stack.