diff --git a/helper/namespace/namespace.go b/helper/namespace/namespace.go
index 1b59495cab845..6e042f84689c6 100644
--- a/helper/namespace/namespace.go
+++ b/helper/namespace/namespace.go
@@ -3,6 +3,7 @@ package namespace
 import (
 	"context"
 	"errors"
+	"fmt"
 	"strings"
 )
 
@@ -13,6 +14,10 @@ type Namespace struct {
 	Path string `json:"path"`
 }
 
+func (n *Namespace) String() string {
+	return fmt.Sprintf("ID: %s. Path: %s", n.ID, n.Path)
+}
+
 const (
 	RootNamespaceID = "root"
 )
diff --git a/vault/auth.go b/vault/auth.go
index ef10a3786f0b6..ab1aeb8272f89 100644
--- a/vault/auth.go
+++ b/vault/auth.go
@@ -7,7 +7,7 @@ import (
 	"strings"
 
 	"github.com/hashicorp/go-secure-stdlib/strutil"
-	uuid "github.com/hashicorp/go-uuid"
+	"github.com/hashicorp/go-uuid"
 	"github.com/hashicorp/vault/builtin/plugin"
 	"github.com/hashicorp/vault/helper/namespace"
 	"github.com/hashicorp/vault/sdk/helper/consts"
@@ -723,16 +723,19 @@ func (c *Core) setupCredentials(ctx context.Context) error {
 		path := credentialRoutePrefix + entry.Path
 		err = c.router.Mount(backend, path, entry, view)
 		if err != nil {
-			c.logger.Error("failed to mount auth entry", "path", entry.Path, "error", err)
+			c.logger.Error("failed to mount auth entry", "path", entry.Path, "namespace", entry.Namespace(), "error", err)
 			return errLoadAuthFailed
 		}
 
 		if c.logger.IsInfo() {
-			c.logger.Info("successfully enabled credential backend", "type", entry.Type, "path", entry.Path)
+			c.logger.Info("successfully enabled credential backend", "type", entry.Type, "path", entry.Path, "namespace", entry.Namespace())
 		}
 
 		// Ensure the path is tainted if set in the mount table
 		if entry.Tainted {
+			// Calculate any namespace prefixes here, because when Taint() is called, there won't be
+			// a namespace to pull from the context. This is similar to what we do above in c.router.Mount().
+			path = entry.Namespace().Path + path
 			c.router.Taint(ctx, path)
 		}
 
diff --git a/vault/router.go b/vault/router.go
index 6426e4eb8f206..489cadf7e7cbe 100644
--- a/vault/router.go
+++ b/vault/router.go
@@ -9,9 +9,9 @@ import (
 	"sync/atomic"
 	"time"
 
-	metrics "github.com/armon/go-metrics"
-	radix "github.com/armon/go-radix"
-	hclog "github.com/hashicorp/go-hclog"
+	"github.com/armon/go-metrics"
+	"github.com/armon/go-radix"
+	"github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/go-secure-stdlib/strutil"
 	"github.com/hashicorp/vault/helper/namespace"
 	"github.com/hashicorp/vault/sdk/helper/consts"
@@ -522,15 +522,27 @@ func (r *Router) routeCommon(ctx context.Context, req *logical.Request, existenc
 	r.l.RLock()
 	adjustedPath := req.Path
 	mount, raw, ok := r.root.LongestPrefix(ns.Path + adjustedPath)
+	if r.logger.IsTrace() {
+		r.logger.Trace("trying to route to mount using adjusted path", "namespace", ns, "adjustedPath", adjustedPath)
+		if !ok {
+			r.logger.Trace("prefix search returned", "mount", mount, "raw", raw)
+		}
+	}
 	if !ok && !strings.HasSuffix(adjustedPath, "/") {
 		// Re-check for a backend by appending a slash. This lets "foo" mean
 		// "foo/" at the root level which is almost always what we want.
 		adjustedPath += "/"
 		mount, raw, ok = r.root.LongestPrefix(ns.Path + adjustedPath)
+		if r.logger.IsTrace() {
+			r.logger.Trace("after appending / to adjustedPath, trying again to route to mount using adjusted path", "namespace", ns, "adjustedPath", adjustedPath)
+			if !ok {
+				r.logger.Trace("after appending / to adjustedPath, prefix search returned", "mount", mount, "raw", raw)
+			}
+		}
 	}
 	r.l.RUnlock()
 	if !ok {
-		return logical.ErrorResponse(fmt.Sprintf("no handler for route '%s'", req.Path)), false, false, logical.ErrUnsupportedPath
+		return logical.ErrorResponse(fmt.Sprintf("no handler for route '%s', route entry not found", req.Path)), false, false, logical.ErrUnsupportedPath
 	}
 	req.Path = adjustedPath
 	defer metrics.MeasureSince([]string{
@@ -551,7 +563,10 @@ func (r *Router) routeCommon(ctx context.Context, req *logical.Request, existenc
 
 	// Filtered mounts will have a nil backend
 	if re.backend == nil {
-		return logical.ErrorResponse(fmt.Sprintf("no handler for route '%s'", req.Path)), false, false, logical.ErrUnsupportedPath
+		if r.logger.IsTrace() {
+			r.logger.Trace("route entry found, but backend is nil")
+		}
+		return logical.ErrorResponse(fmt.Sprintf("no handler for route '%s', nil backend", req.Path)), false, false, logical.ErrUnsupportedPath
 	}
 
 	// If the path is tainted, we reject any operation except for
@@ -560,7 +575,10 @@ func (r *Router) routeCommon(ctx context.Context, req *logical.Request, existenc
 		switch req.Operation {
 		case logical.RevokeOperation, logical.RollbackOperation:
 		default:
-			return logical.ErrorResponse(fmt.Sprintf("no handler for route '%s'", req.Path)), false, false, logical.ErrUnsupportedPath
+			if r.logger.IsTrace() {
+				r.logger.Trace("route entry is tainted, rejecting operations to it that aren't revoke or rollback")
+			}
+			return logical.ErrorResponse(fmt.Sprintf("no handler for route '%s', entry tainted", req.Path)), false, false, logical.ErrUnsupportedPath
 		}
 	}