diff --git a/addons/mail/static/src/models/thread/thread.js b/addons/mail/static/src/models/thread/thread.js
index 9bedc8096bc..03687e19b48 100644
--- a/addons/mail/static/src/models/thread/thread.js
+++ b/addons/mail/static/src/models/thread/thread.js
@@ -547,8 +547,9 @@ function factory(dependencies) {
         openExpanded() {
             const discuss = this.env.messaging.discuss;
             if (['mail.channel', 'mail.box'].includes(this.model)) {
+                discuss.threadViewer.update({ thread: [['replace', this]] });
                 this.env.bus.trigger('do-action', {
-                    action: 'mail.action_new_discuss',
+                    action: 'mail.action_discuss',
                     options: {
                         clear_breadcrumbs: false,
                         active_id: discuss.threadToActiveId(this),
diff --git a/odoo/tests/common.py b/odoo/tests/common.py
index 7c032ac58ee..84ab36e5008 100644
--- a/odoo/tests/common.py
+++ b/odoo/tests/common.py
@@ -1402,7 +1402,7 @@ class HttpCase(TransactionCase):
         `browser_js` can be passed as keyword arguments."""
         step_delay = ', %s' % step_delay if step_delay else ''
         code = kwargs.pop('code', "odoo.startTour('%s'%s)" % (tour_name, step_delay))
-        ready = kwargs.pop('ready', "odoo.__DEBUG__.services['web_tour.tour'].tours.%s.ready" % tour_name)
+        ready = kwargs.pop('ready', "odoo.__DEBUG__.services['web_tour.tour'].tours['%s'].ready" % tour_name)
         res = self.browser_js(url_path=url_path, code=code, ready=ready, **kwargs)
         # some tests read the result after the tour, and as  the tour does not
         # use this environment's cache, invalidate it to fetch the data from the