diff --git a/src/main/frontend/format/mldoc.cljs b/src/main/frontend/format/mldoc.cljs
index 98ba8c112b..638bf1b300 100644
--- a/src/main/frontend/format/mldoc.cljs
+++ b/src/main/frontend/format/mldoc.cljs
@@ -231,17 +231,19 @@
 
 (defn ->edn
   [content config]
-  (try
-    (if (string/blank? content)
-      []
-      (-> content
-          (parse-json config)
-          (util/json->clj)
-          (update-src-full-content content)
-          (collect-page-properties)))
-    (catch js/Error e
-      (log/error :edn/convert-failed e)
-      [])))
+  (if (string? content)
+    (try
+      (if (string/blank? content)
+        []
+        (-> content
+            (parse-json config)
+            (util/json->clj)
+            (update-src-full-content content)
+            (collect-page-properties)))
+      (catch js/Error e
+        (log/error :edn/convert-failed e)
+        []))
+    (log/error :edn/wrong-content-type content)))
 
 (defn ->edn-async
   [content config]
diff --git a/src/main/frontend/handler/editor.cljs b/src/main/frontend/handler/editor.cljs
index 70c6791e2b..3370153c25 100644
--- a/src/main/frontend/handler/editor.cljs
+++ b/src/main/frontend/handler/editor.cljs
@@ -578,18 +578,19 @@
          :pos pos}))))
 
 (defn- with-marker-time
-  [content format new-marker old-marker]
+  [content block format new-marker old-marker]
   (if (and (state/enable-timetracking?) new-marker)
     (try
-      (let [new-marker (string/trim (string/lower-case (name new-marker)))
+      (let [logbook-exists? (and (:block/body block) (clock/get-logbook (:block/body block)))
+            new-marker (string/trim (string/lower-case (name new-marker)))
             old-marker (when old-marker (string/trim (string/lower-case (name old-marker))))
             new-content (cond
                           (or (and (nil? old-marker) (or (= new-marker "doing")
                                                          (= new-marker "now")))
                               (and (= old-marker "todo") (= new-marker "doing"))
                               (and (= old-marker "later") (= new-marker "now"))
-                              (= old-marker new-marker "now")
-                              (= old-marker new-marker "doing"))
+                              (and (= old-marker new-marker "now") (not logbook-exists?))
+                              (and (= old-marker new-marker "doing") (not logbook-exists?)))
                           (clock/clock-in format content)
 
                           (or
@@ -610,7 +611,7 @@
   [block value]
   (if (state/enable-timetracking?)
     (let [new-marker (first (util/safe-re-find marker/bare-marker-pattern (or value "")))
-          new-value (with-marker-time value (:block/format block)
+          new-value (with-marker-time value block (:block/format block)
                       new-marker
                       (:block/marker block))]
       new-value)
@@ -799,7 +800,7 @@
                      (if repeated?
                        (update-timestamps-content! block content)
                        new-content)
-                     (with-marker-time format "DONE" marker))]
+                     (with-marker-time block format "DONE" marker))]
     (save-block-if-changed! block new-content)))
 
 (defn uncheck
@@ -808,7 +809,7 @@
                  "LATER"
                  "TODO")
         new-content (-> (string/replace-first content "DONE" marker)
-                        (with-marker-time format marker "DONE"))]
+                        (with-marker-time block format marker "DONE"))]
     (save-block-if-changed! block new-content)))
 
 (defn cycle-todo!
@@ -829,7 +830,7 @@
 (defn set-marker
   [{:block/keys [uuid marker content format properties] :as block} new-marker]
   (let [new-content (-> (string/replace-first content (re-pattern (str "^" marker)) new-marker)
-                        (with-marker-time format new-marker marker))]
+                        (with-marker-time block format new-marker marker))]
     (save-block-if-changed! block new-content)))
 
 (defn set-priority
diff --git a/src/main/frontend/util/clock.cljs b/src/main/frontend/util/clock.cljs
index 62141c106c..3f8076e1d6 100644
--- a/src/main/frontend/util/clock.cljs
+++ b/src/main/frontend/util/clock.cljs
@@ -48,12 +48,16 @@
          (str clock-out-log "\n"))))
     content))
 
+(defn get-logbook
+  [body]
+  (-> (filter (fn [v] (and (vector? v)
+                          (= (first v) "Drawer")
+                          (= (second v) "logbook"))) body)
+      first))
+
 (defn clock-summary
   [body string?]
-  (when-let [logbook (-> (filter (fn [v] (and (vector? v)
-                                          (= (first v) "Drawer")
-                                          (= (second v) "logbook"))) body)
-                         first)]
+  (when-let [logbook (get-logbook body)]
     (when-let [clock-lines (last logbook)]
       (let [times (map #(string/trim (last (string/split % "=>"))) clock-lines)
             hours (map #(int (first (string/split % ":"))) times)