diff --git a/rojo-test/syncback-test-snapshots/end_to_end__rojo_test__syncback_util__child_but_not.snap b/rojo-test/syncback-test-snapshots/end_to_end__rojo_test__syncback_util__child_but_not.snap
new file mode 100644
index 000000000..c5b70248b
--- /dev/null
+++ b/rojo-test/syncback-test-snapshots/end_to_end__rojo_test__syncback_util__child_but_not.snap
@@ -0,0 +1,14 @@
+---
+source: tests/rojo_test/syncback_util.rs
+assertion_line: 48
+expression: "visualize_fs_snapshot(&fs_snapshot, &output_path)"
+---
+added_files:
+  - "OnlyOneCopy\\child_of_one.luau"
+  - "ReplicatedStorage\\child_replicated_storage.luau"
+added_dirs:
+  - OnlyOneCopy
+  - ReplicatedStorage
+removed_files: []
+removed_dirs: []
+
diff --git a/rojo-test/syncback-tests/child_but_not/expected/OnlyOneCopy/child_of_one.luau b/rojo-test/syncback-tests/child_but_not/expected/OnlyOneCopy/child_of_one.luau
new file mode 100644
index 000000000..d23f92e7f
--- /dev/null
+++ b/rojo-test/syncback-tests/child_but_not/expected/OnlyOneCopy/child_of_one.luau
@@ -0,0 +1 @@
+-- displace personality beam leadership occupy
diff --git a/rojo-test/syncback-tests/child_but_not/expected/ReplicatedStorage/child_replicated_storage.luau b/rojo-test/syncback-tests/child_but_not/expected/ReplicatedStorage/child_replicated_storage.luau
new file mode 100644
index 000000000..dc3e15bf4
--- /dev/null
+++ b/rojo-test/syncback-tests/child_but_not/expected/ReplicatedStorage/child_replicated_storage.luau
@@ -0,0 +1 @@
+-- skate bottle vain nonsense tablet
diff --git a/rojo-test/syncback-tests/child_but_not/expected/default.project.json b/rojo-test/syncback-tests/child_but_not/expected/default.project.json
new file mode 100644
index 000000000..d23f524c2
--- /dev/null
+++ b/rojo-test/syncback-tests/child_but_not/expected/default.project.json
@@ -0,0 +1,12 @@
+{
+  "name": "child_but_not",
+  "tree": {
+    "$className": "DataModel",
+    "ReplicatedStorage": {
+      "$path": "ReplicatedStorage",
+      "OnlyOneCopy": {
+        "$path": "OnlyOneCopy"
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/rojo-test/syncback-tests/child_but_not/input.rbxl b/rojo-test/syncback-tests/child_but_not/input.rbxl
new file mode 100644
index 000000000..9723a9142
Binary files /dev/null and b/rojo-test/syncback-tests/child_but_not/input.rbxl differ
diff --git a/rojo-test/syncback-tests/child_but_not/output/default.project.json b/rojo-test/syncback-tests/child_but_not/output/default.project.json
new file mode 100644
index 000000000..d23f524c2
--- /dev/null
+++ b/rojo-test/syncback-tests/child_but_not/output/default.project.json
@@ -0,0 +1,12 @@
+{
+  "name": "child_but_not",
+  "tree": {
+    "$className": "DataModel",
+    "ReplicatedStorage": {
+      "$path": "ReplicatedStorage",
+      "OnlyOneCopy": {
+        "$path": "OnlyOneCopy"
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/snapshot_middleware/dir.rs b/src/snapshot_middleware/dir.rs
index 3ebfce618..e63ea5b4a 100644
--- a/src/snapshot_middleware/dir.rs
+++ b/src/snapshot_middleware/dir.rs
@@ -7,7 +7,7 @@ use anyhow::Context;
 use memofs::{DirEntry, IoResultExt, Vfs};
 
 use crate::{
-    snapshot::{InstanceContext, InstanceMetadata, InstanceSnapshot},
+    snapshot::{InstanceContext, InstanceMetadata, InstanceSnapshot, InstigatingSource},
     syncback::{FsSnapshot, SyncbackReturn, SyncbackSnapshot},
 };
 
@@ -173,6 +173,15 @@ pub fn syncback_dir_no_meta<'sync>(
                         old_child.name()
                     );
                     continue;
+                } else if matches!(
+                    old_child.metadata().instigating_source,
+                    Some(InstigatingSource::ProjectNode { .. })
+                ) {
+                    log::debug!(
+                        "Skipping instance {} because it originates in a project file",
+                        old_child.name()
+                    );
+                    continue;
                 }
                 // This child exists in both doms. Pass it on.
                 children.push(snapshot.with_joined_path(*new_child_ref, Some(old_child.id()))?);
diff --git a/src/snapshot_middleware/rbxmx.rs b/src/snapshot_middleware/rbxmx.rs
index e86b5f430..52551cd5e 100644
--- a/src/snapshot_middleware/rbxmx.rs
+++ b/src/snapshot_middleware/rbxmx.rs
@@ -2,6 +2,7 @@ use std::path::Path;
 
 use anyhow::Context;
 use memofs::Vfs;
+use rbx_xml::EncodeOptions;
 
 use crate::{
     snapshot::{InstanceContext, InstanceMetadata, InstanceSnapshot},
@@ -18,7 +19,7 @@ pub fn snapshot_rbxmx(
         .property_behavior(rbx_xml::DecodePropertyBehavior::ReadUnknown);
 
     let temp_tree = rbx_xml::from_reader(vfs.read(path)?.as_slice(), options)
-        .with_context(|| format!("Malformed rbxm file: {}", path.display()))?;
+        .with_context(|| format!("Malformed rbxmx file: {}", path.display()))?;
 
     let root_instance = temp_tree.root();
     let children = root_instance.children();
@@ -49,11 +50,19 @@ pub fn syncback_rbxmx<'sync>(
 ) -> anyhow::Result<SyncbackReturn<'sync>> {
     let inst = snapshot.new_inst();
 
+    let options =
+        EncodeOptions::new().property_behavior(rbx_xml::EncodePropertyBehavior::WriteUnknown);
+
     // Long-term, we probably want to have some logic for if this contains a
     // script. That's a future endeavor though.
     let mut serialized = Vec::new();
-    rbx_xml::to_writer_default(&mut serialized, snapshot.new_tree(), &[inst.referent()])
-        .context("failed to serialize new rbxmx")?;
+    rbx_xml::to_writer(
+        &mut serialized,
+        snapshot.new_tree(),
+        &[inst.referent()],
+        options,
+    )
+    .context("failed to serialize new rbxmx")?;
 
     Ok(SyncbackReturn {
         inst_snapshot: InstanceSnapshot::from_instance(inst),
diff --git a/src/variant_eq.rs b/src/variant_eq.rs
index 0db78a5e8..d99addc62 100644
--- a/src/variant_eq.rs
+++ b/src/variant_eq.rs
@@ -124,16 +124,16 @@ pub fn variant_eq(variant_a: &Variant, variant_b: &Variant) -> bool {
             }
             true
         }
-        (Variant::OptionalCFrame(a), Variant::OptionalCFrame(b)) => {
-            if let (Some(a2), Some(b2)) = (a, b) {
-                vector_eq(&a2.position, &b2.position)
-                    && vector_eq(&a2.orientation.x, &b2.orientation.x)
-                    && vector_eq(&a2.orientation.y, &b2.orientation.y)
-                    && vector_eq(&a2.orientation.z, &b2.orientation.z)
-            } else {
-                false
+        (Variant::OptionalCFrame(a), Variant::OptionalCFrame(b)) => match (a, b) {
+            (Some(a), Some(b)) => {
+                vector_eq(&a.position, &b.position)
+                    && vector_eq(&a.orientation.x, &b.orientation.x)
+                    && vector_eq(&a.orientation.y, &b.orientation.y)
+                    && vector_eq(&a.orientation.z, &b.orientation.z)
             }
-        }
+            (None, None) => true,
+            _ => false,
+        },
         (Variant::PhysicalProperties(a), Variant::PhysicalProperties(b)) => match (a, b) {
             (PhysicalProperties::Default, PhysicalProperties::Default) => true,
             (PhysicalProperties::Custom(a2), PhysicalProperties::Custom(b2)) => {
@@ -143,7 +143,7 @@ pub fn variant_eq(variant_a: &Variant, variant_b: &Variant) -> bool {
                     && approx_eq!(f32, a2.elasticity_weight, b2.elasticity_weight)
                     && approx_eq!(f32, a2.friction_weight, b2.friction_weight)
             }
-            (_, _) => false,
+            _ => false,
         },
         (Variant::Ray(a), Variant::Ray(b)) => {
             vector_eq(&a.direction, &b.direction) && vector_eq(&a.origin, &b.origin)
diff --git a/tests/tests/syncback.rs b/tests/tests/syncback.rs
index b51562953..f351426e0 100644
--- a/tests/tests/syncback.rs
+++ b/tests/tests/syncback.rs
@@ -28,4 +28,5 @@ syncback_basic_test! {
     project_all_middleware,
     duplicate_rojo_id,
     string_value_project,
+    child_but_not,
 }