diff --git a/core/core-projects.el b/core/core-projects.el
index 2fce0b554..d4ba241a3 100644
--- a/core/core-projects.el
+++ b/core/core-projects.el
@@ -39,23 +39,6 @@ Emacs.")
   :config
   (projectile-mode +1)
 
-  ;; REVIEW Resolve the project root once, when the file/buffer is opened. This
-  ;;        speeds up projectile's project root resolution by leaps, but does
-  ;;        put you at risk of having a stale project root.
-  (setq-hook! '(change-major-mode-after-body-hook
-                ;; In case the user saves the file to a new location
-                after-save-hook
-                ;; ...or makes external changes then returns to Emacs
-                focus-in-hook
-                ;; ...or when we change the current project!
-                projectile-after-switch-project-hook)
-    projectile-project-root (if default-directory (doom-project-root)))
-
-  ;; However, it may become a problem when switching projects, so remove the
-  ;; cached value when switching projects.
-  (setq-hook! 'projectile-before-switch-project-hook
-    projectile-project-root nil)
-
   ;; Projectile runs four functions to determine the root (in this order):
   ;;
   ;; + `projectile-root-local' -> checks the `projectile-project-root' variable
diff --git a/modules/ui/workspaces/autoload/workspaces.el b/modules/ui/workspaces/autoload/workspaces.el
index de856b4bf..681bf43b5 100644
--- a/modules/ui/workspaces/autoload/workspaces.el
+++ b/modules/ui/workspaces/autoload/workspaces.el
@@ -525,42 +525,46 @@ the user to open a file in the new project.
 This be hooked to `projectile-after-switch-project-hook'."
   (when dir
     (setq +workspaces--project-dir dir))
-  (when (and persp-mode +workspaces--project-dir)
-    (when projectile-before-switch-project-hook
-      (with-temp-buffer
-        ;; Load the project dir-local variables into the switch buffer, so the
-        ;; action can make use of them
-        (setq default-directory +workspaces--project-dir)
-        (hack-dir-local-variables-non-file-buffer)
-        (run-hooks 'projectile-before-switch-project-hook)))
-    (unwind-protect
-        (if (and (not (null +workspaces-on-switch-project-behavior))
-                 (or (eq +workspaces-on-switch-project-behavior t)
-                     (equal (safe-persp-name (get-current-persp)) persp-nil-name)
-                     (+workspace-buffer-list)))
-            (let* ((persp
-                    (let ((project-name (doom-project-name +workspaces--project-dir)))
-                      (or (+workspace-get project-name t)
-                          (+workspace-new project-name))))
-                   (new-name (persp-name persp)))
-              (+workspace-switch new-name)
-              (with-current-buffer (doom-fallback-buffer)
-                (setq default-directory +workspaces--project-dir))
-              (unless current-prefix-arg
-                (funcall +workspaces-switch-project-function +workspaces--project-dir))
-              (+workspace-message
-               (format "Switched to '%s' in new workspace" new-name)
-               'success))
-          (with-current-buffer (doom-fallback-buffer)
-            (setq default-directory +workspaces--project-dir)
-            (hack-dir-local-variables-non-file-buffer)
-            (message "Switched to '%s'" (doom-project-name +workspaces--project-dir)))
-          (with-demoted-errors "Workspace error: %s"
-            (+workspace-rename (+workspace-current-name) (doom-project-name +workspaces--project-dir)))
-          (unless current-prefix-arg
-            (funcall +workspaces-switch-project-function +workspaces--project-dir)))
-      (run-hooks 'projectile-after-switch-project-hook)
-      (setq +workspaces--project-dir nil))))
+  ;; HACK Clear projectile-project-root, otherwise cached roots may interfere
+  ;;      with project switch (see #3166)
+  (let (projectile-project-root)
+    (when (and persp-mode +workspaces--project-dir)
+      (when projectile-before-switch-project-hook
+        (with-temp-buffer
+          ;; Load the project dir-local variables into the switch buffer, so the
+          ;; action can make use of them
+          (setq default-directory +workspaces--project-dir)
+          (hack-dir-local-variables-non-file-buffer)
+          (run-hooks 'projectile-before-switch-project-hook)))
+      (unwind-protect
+          (if (and (not (null +workspaces-on-switch-project-behavior))
+                   (or (eq +workspaces-on-switch-project-behavior t)
+                       (equal (safe-persp-name (get-current-persp)) persp-nil-name)
+                       (+workspace-buffer-list)))
+              (let* ((persp
+                      (let ((project-name (doom-project-name +workspaces--project-dir)))
+                        (or (+workspace-get project-name t)
+                            (+workspace-new project-name))))
+                     (new-name (persp-name persp)))
+                (+workspace-switch new-name)
+                (with-current-buffer (doom-fallback-buffer)
+                  (setq default-directory +workspaces--project-dir)
+                  (hack-dir-local-variables-non-file-buffer))
+                (unless current-prefix-arg
+                  (funcall +workspaces-switch-project-function +workspaces--project-dir))
+                (+workspace-message
+                 (format "Switched to '%s' in new workspace" new-name)
+                 'success))
+            (with-current-buffer (doom-fallback-buffer)
+              (setq default-directory +workspaces--project-dir)
+              (hack-dir-local-variables-non-file-buffer)
+              (message "Switched to '%s'" (doom-project-name +workspaces--project-dir)))
+            (with-demoted-errors "Workspace error: %s"
+              (+workspace-rename (+workspace-current-name) (doom-project-name +workspaces--project-dir)))
+            (unless current-prefix-arg
+              (funcall +workspaces-switch-project-function +workspaces--project-dir)))
+        (run-hooks 'projectile-after-switch-project-hook)
+        (setq +workspaces--project-dir nil)))))
 
 
 ;;