diff --git a/addons/mail/controllers/discuss.py b/addons/mail/controllers/discuss.py
index 3ef41e6901d..dc8f575b0f8 100644
--- a/addons/mail/controllers/discuss.py
+++ b/addons/mail/controllers/discuss.py
@@ -416,7 +416,8 @@ class DiscussController(http.Controller):
                 'is_active': follower.is_active,
                 # When editing the followers, the "pencil" icon that leads to the edition of subtypes
                 # should be always be displayed and not only when "debug" mode is activated.
-                'is_editable': True
+                'is_editable': True,
+                'partner': follower.partner_id.mail_partner_format()[follower.partner_id],
             })
         return {
             'followers': followers,
diff --git a/addons/mail/models/res_partner.py b/addons/mail/models/res_partner.py
index 681a42c72d4..2907006766c 100644
--- a/addons/mail/models/res_partner.py
+++ b/addons/mail/models/res_partner.py
@@ -187,7 +187,7 @@ class Partner(models.Model):
     @api.model
     def get_mention_suggestions(self, search, limit=8, channel_id=None):
         """ Return 'limit'-first partners' such that the name or email matches a 'search' string.
-            Prioritize partners that are also users, and then extend the research to all partners.
+            Prioritize partners that are also (internal) users, and then extend the research to all partners.
             If channel_id is given, only members of this channel are returned.
             The return format is a list of partner data (as per returned by `mail_partner_format()`).
         """
@@ -195,16 +195,18 @@ class Partner(models.Model):
         search_dom = expression.AND([[('active', '=', True), ('type', '!=', 'private')], search_dom])
         if channel_id:
             search_dom = expression.AND([[('channel_ids', 'in', channel_id)], search_dom])
-
-        # Search partners that are also users
-        domain = expression.AND([[('user_ids.id', '!=', False), ('user_ids.active', '=', True)], search_dom])
-        partners = self.search(domain, limit=limit)
-
-        # Search partners that are not users if less than 'limit' partner that are users found
-        remaining_limit = limit - len(partners)
-        if remaining_limit > 0:
-            partners |= self.search(expression.AND([[('id', 'not in', partners.ids)], search_dom]), limit=remaining_limit)
-
+        domain_is_user = expression.AND([[('user_ids.id', '!=', False), ('user_ids.active', '=', True)], search_dom])
+        priority_conditions = [
+            expression.AND([domain_is_user, [('partner_share', '=', False)]]),  # Search partners that are internal users
+            domain_is_user,  # Search partners that are users
+            search_dom,  # Search partners that are not users
+        ]
+        partners = self.env['res.partner']
+        for domain in priority_conditions:
+            remaining_limit = limit - len(partners)
+            if remaining_limit <= 0:
+                break
+            partners |= self.search(expression.AND([[('id', 'not in', partners.ids)], domain]), limit=remaining_limit)
         return list(partners.mail_partner_format().values())
 
     @api.model
diff --git a/addons/mail/static/src/models/follower/follower.js b/addons/mail/static/src/models/follower/follower.js
index 68fdcfb2118..13b7e713f6c 100644
--- a/addons/mail/static/src/models/follower/follower.js
+++ b/addons/mail/static/src/models/follower/follower.js
@@ -36,6 +36,9 @@ registerModel({
                     data2.partner = insert(partnerData);
                 }
             }
+            if (data.partner) {
+                data2.partner = insertAndReplace(this.models['mail.partner'].convertData(data.partner));
+            }
             return data2;
         },
     },
diff --git a/addons/mail/tests/test_res_partner.py b/addons/mail/tests/test_res_partner.py
index be9784d0717..c2fb68464c2 100644
--- a/addons/mail/tests/test_res_partner.py
+++ b/addons/mail/tests/test_res_partner.py
@@ -1,7 +1,9 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
-from odoo.addons.mail.tests.common import MailCommon
+from uuid import uuid4
+
+from odoo.addons.mail.tests.common import MailCommon, mail_new_test_user
 from odoo.tests.common import Form, users
 
 
@@ -126,6 +128,17 @@ class TestPartner(MailCommon):
         self.assertIn('Portal Access Granted', new_msg.body)
         self.assertEqual(new_msg.subtype_id, subtype_note)
 
+    def test_res_partner_get_mention_suggestions_priority(self):
+        name = uuid4()  # unique name to avoid conflict with already existing users
+        self.env['res.partner'].create([{'name': f'{name}-{i}-not-user'} for i in range(0, 2)])
+        for i in range(0, 2):
+            mail_new_test_user(self.env, login=f'{name}-{i}-portal-user', groups='base.group_portal')
+            mail_new_test_user(self.env, login=f'{name}-{i}-internal-user', groups='base.group_user')
+        partners_format = self.env['res.partner'].get_mention_suggestions(name, limit=5)
+        self.assertEqual(len(partners_format), 5, "should have found limit (5) partners")
+        self.assertEqual(list(map(lambda p: p['is_internal_user'], partners_format)), [True, True, False, False, False], "should return internal users in priority")
+        self.assertEqual(list(map(lambda p: bool(p['user_id']), partners_format)), [True, True, True, True, False], "should return partners without users last")
+
     @users('admin')
     def test_res_partner_merge_wizards(self):
         Partner = self.env['res.partner']