diff --git a/addons/web/static/src/js/report/client_action.js b/addons/web/static/src/js/report/client_action.js
index 9b7d1fb6124..d4cb3096aea 100644
--- a/addons/web/static/src/js/report/client_action.js
+++ b/addons/web/static/src/js/report/client_action.js
@@ -53,15 +53,6 @@ var ReportAction = AbstractAction.extend({
         });
     },
 
-    do_show: function () {
-        this.updateControlPanel({
-            cp_content: {
-                $buttons: this.$buttons,
-            },
-        });
-        return this._super.apply(this, arguments);
-    },
-
     on_attach_callback: function () {
         // Register now the postMessage event handler. We only want to listen to ~trusted
         // messages and we can only filter them by their origin, so we chose to ignore the
diff --git a/addons/web/static/tests/report/client_action_tests.js b/addons/web/static/tests/report/client_action_tests.js
new file mode 100644
index 00000000000..c537f6c2540
--- /dev/null
+++ b/addons/web/static/tests/report/client_action_tests.js
@@ -0,0 +1,111 @@
+odoo.define('web/static/tests/report/client_action_tests', function (require) {
+    "use strict";
+
+    const ControlPanel = require('web.ControlPanel');
+    const ReportClientAction = require('report.client_action');
+    const testUtils = require("web.test_utils");
+
+    const { createActionManager, dom, mock } = testUtils;
+
+    QUnit.module('Client Action Report', {}, () => {
+        QUnit.test("mounted is called once when returning on 'Client Action Report' from breadcrumb", async assert => {
+            // This test can be removed as soon as we don't mix legacy and owl layers anymore.
+            assert.expect(7);
+
+            let mountCount = 0;
+
+            // patch the report client action to override its iframe's url so that
+            // it doesn't trigger an RPC when it is appended to the DOM (for this
+            // usecase, using removeSRCAttribute doesn't work as the RPC is
+            // triggered as soon as the iframe is in the DOM, even if its src
+            // attribute is removed right after)
+            mock.patch(ReportClientAction, {
+                start: function () {
+                    var self = this;
+                    return this._super.apply(this, arguments).then(function () {
+                        self._rpc({route: self.iframe.getAttribute('src')});
+                        self.iframe.setAttribute('src', 'about:blank');
+                    });
+                }
+            });
+
+            ControlPanel.patch('test.ControlPanel', T => {
+                class ControlPanelPatchTest extends T {
+                    mounted() {
+                        mountCount = mountCount + 1;
+                        this.__uniqueId = mountCount;
+                        assert.step(`mounted ${this.__uniqueId}`);
+                        super.mounted(...arguments);
+                    }
+                    willUnmount() {
+                        assert.step(`willUnmount ${this.__uniqueId}`);
+                        super.mounted(...arguments);
+                    }
+                }
+                return ControlPanelPatchTest;
+            });
+            const actionManager = await createActionManager({
+                actions: [
+                    {
+                        id: 42,
+                        name: "Client Action Report",
+                        tag: 'report.client_action',
+                        type: 'ir.actions.report',
+                        report_type: 'qweb-html',
+                    },
+                    {
+                        id: 43,
+                        type: "ir.actions.act_window",
+                        res_id: 1,
+                        res_model: "partner",
+                        views: [
+                            [false, "form"],
+                        ],
+                    }
+                ],
+                archs: {
+                    'partner,false,form': '<form><field name="display_name"/></form>',
+                    'partner,false,search': '<search></search>',
+                },
+                data: {
+                    partner: {
+                        fields: {
+                            display_name: { string: "Displayed name", type: "char" },
+                        },
+                        records: [
+                            {id: 1, display_name: "Genda Swami"},
+                        ],
+                    },
+                },
+                mockRPC: function (route) {
+                    if (route === '/report/html/undefined?context=%7B%7D') {
+                        return Promise.resolve('<a action="go_to_details">Go to detail view</a>');
+                    }
+                    return this._super.apply(this, arguments);
+                },
+                intercepts: {
+                    do_action: ev => actionManager.doAction(ev.data.action, ev.data.options),
+                },
+            });
+
+            await actionManager.doAction(42);
+            // simulate an action as we are not able to reproduce a real doAction using 'Client Action Report'
+            await actionManager.doAction(43);
+            await dom.click(actionManager.$('.breadcrumb-item:first'));
+            actionManager.destroy();
+
+            assert.verifySteps([
+                'mounted 1',
+                'willUnmount 1',
+                'mounted 2',
+                'willUnmount 2',
+                'mounted 3',
+                'willUnmount 3',
+            ]);
+
+            ControlPanel.unpatch('test.ControlPanel');
+            mock.unpatch(ReportClientAction);
+        });
+    });
+
+});
diff --git a/addons/web/views/webclient_templates.xml b/addons/web/views/webclient_templates.xml
index 763117ec968..7effc9952da 100644
--- a/addons/web/views/webclient_templates.xml
+++ b/addons/web/views/webclient_templates.xml
@@ -778,6 +778,8 @@
         <script type="text/javascript" src="/web/static/tests/widgets/model_field_selector_tests.js"/>
         <script type="text/javascript" src="/web/static/tests/widgets/rainbow_man_tests.js"/>
 
+        <script type="text/javascript" src="/web/static/tests/report/client_action_tests.js"/>
+
         <script type="text/javascript" src="/web/static/tests/tools/debug_manager_tests.js"/>
 
         <script type="text/javascript" src="/web/static/tests/helpers/test_utils_tests.js"></script>