diff --git a/.changelog/14675.txt b/.changelog/14675.txt
new file mode 100644
index 00000000000..2efa8ce2bb1
--- /dev/null
+++ b/.changelog/14675.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+csi: Fixed a bug where a volume that was successfully unmounted by the client but then failed controller unpublishing would not be marked free until garbage collection ran.
+```
diff --git a/nomad/core_sched_test.go b/nomad/core_sched_test.go
index 1ec20f538d8..8ca4e7a2ef6 100644
--- a/nomad/core_sched_test.go
+++ b/nomad/core_sched_test.go
@@ -2459,7 +2459,7 @@ func TestCoreScheduler_CSIBadState_ClaimGC(t *testing.T) {
 			}
 		}
 		return true
-	}, time.Second*1, 10*time.Millisecond, "invalid claims should be marked for GC")
+	}, time.Second*5, 10*time.Millisecond, "invalid claims should be marked for GC")
 
 }
 
diff --git a/nomad/csi_endpoint.go b/nomad/csi_endpoint.go
index cdf3d4cd395..d3cd71cdab6 100644
--- a/nomad/csi_endpoint.go
+++ b/nomad/csi_endpoint.go
@@ -574,6 +574,16 @@ func (v *CSIVolume) Unpublish(args *structs.CSIVolumeUnpublishRequest, reply *st
 
 	claim := args.Claim
 
+	// we need to checkpoint when we first get the claim to ensure we've set the
+	// initial "past claim" state, otherwise a client that unpublishes (skipping
+	// the node unpublish b/c it's done that work) fail to get written if the
+	// controller unpublish fails.
+	vol = vol.Copy()
+	err = v.checkpointClaim(vol, claim)
+	if err != nil {
+		return err
+	}
+
 	// previous checkpoints may have set the past claim state already.
 	// in practice we should never see CSIVolumeClaimStateControllerDetached
 	// but having an option for the state makes it easy to add a checkpoint
@@ -619,6 +629,13 @@ RELEASE_CLAIM:
 // problems. This function should only be called on a copy of the volume.
 func (v *CSIVolume) nodeUnpublishVolume(vol *structs.CSIVolume, claim *structs.CSIVolumeClaim) error {
 	v.logger.Trace("node unpublish", "vol", vol.ID)
+
+	// We need a new snapshot after each checkpoint
+	snap, err := v.srv.fsm.State().Snapshot()
+	if err != nil {
+		return err
+	}
+
 	if claim.AllocationID != "" {
 		err := v.nodeUnpublishVolumeImpl(vol, claim)
 		if err != nil {
@@ -631,8 +648,7 @@ func (v *CSIVolume) nodeUnpublishVolume(vol *structs.CSIVolume, claim *structs.C
 	// The RPC sent from the 'nomad node detach' command or GC won't have an
 	// allocation ID set so we try to unpublish every terminal or invalid
 	// alloc on the node, all of which will be in PastClaims after denormalizing
-	state := v.srv.fsm.State()
-	vol, err := state.CSIVolumeDenormalize(memdb.NewWatchSet(), vol)
+	vol, err = snap.CSIVolumeDenormalize(memdb.NewWatchSet(), vol)
 	if err != nil {
 		return err
 	}
@@ -702,10 +718,15 @@ func (v *CSIVolume) controllerUnpublishVolume(vol *structs.CSIVolume, claim *str
 		return nil
 	}
 
-	state := v.srv.fsm.State()
+	// We need a new snapshot after each checkpoint
+	snap, err := v.srv.fsm.State().Snapshot()
+	if err != nil {
+		return err
+	}
+
 	ws := memdb.NewWatchSet()
 
-	plugin, err := state.CSIPluginByID(ws, vol.PluginID)
+	plugin, err := snap.CSIPluginByID(ws, vol.PluginID)
 	if err != nil {
 		return fmt.Errorf("could not query plugin: %v", err)
 	} else if plugin == nil {
@@ -717,7 +738,7 @@ func (v *CSIVolume) controllerUnpublishVolume(vol *structs.CSIVolume, claim *str
 		return nil
 	}
 
-	vol, err = state.CSIVolumeDenormalize(ws, vol)
+	vol, err = snap.CSIVolumeDenormalize(ws, vol)
 	if err != nil {
 		return err
 	}
diff --git a/nomad/csi_endpoint_test.go b/nomad/csi_endpoint_test.go
index b8c54d3855e..0a91ec6a04a 100644
--- a/nomad/csi_endpoint_test.go
+++ b/nomad/csi_endpoint_test.go
@@ -568,8 +568,8 @@ func TestCSIVolumeEndpoint_Unpublish(t *testing.T) {
 
 			// setup: create an alloc that will claim our volume
 			alloc := mock.BatchAlloc()
-			alloc.NodeID = node.ID
-			alloc.ClientStatus = structs.AllocClientStatusFailed
+			alloc.NodeID = tc.nodeID
+			alloc.ClientStatus = structs.AllocClientStatusRunning
 
 			otherAlloc := mock.BatchAlloc()
 			otherAlloc.NodeID = tc.otherNodeID
@@ -579,7 +579,7 @@ func TestCSIVolumeEndpoint_Unpublish(t *testing.T) {
 			require.NoError(t, state.UpsertAllocs(structs.MsgTypeTestSetup, index,
 				[]*structs.Allocation{alloc, otherAlloc}))
 
-			// setup: claim the volume for our alloc
+			// setup: claim the volume for our to-be-failed alloc
 			claim := &structs.CSIVolumeClaim{
 				AllocationID:   alloc.ID,
 				NodeID:         node.ID,
@@ -617,10 +617,19 @@ func TestCSIVolumeEndpoint_Unpublish(t *testing.T) {
 				},
 			}
 
+			alloc = alloc.Copy()
+			alloc.ClientStatus = structs.AllocClientStatusFailed
+			index++
+			require.NoError(t, state.UpsertAllocs(structs.MsgTypeTestSetup, index,
+				[]*structs.Allocation{alloc}))
+
 			err = msgpackrpc.CallWithCodec(codec, "CSIVolume.Unpublish", req,
 				&structs.CSIVolumeUnpublishResponse{})
 
-			vol, volErr := state.CSIVolumeByID(nil, ns, volID)
+			snap, snapErr := state.Snapshot()
+			require.NoError(t, snapErr)
+
+			vol, volErr := snap.CSIVolumeByID(nil, ns, volID)
 			require.NoError(t, volErr)
 			require.NotNil(t, vol)