diff --git a/src/libs/ReportUtils.ts b/src/libs/ReportUtils.ts
index 3451e14e388b..7da99d3ca8e6 100644
--- a/src/libs/ReportUtils.ts
+++ b/src/libs/ReportUtils.ts
@@ -293,6 +293,7 @@ type OptimisticChatReport = Pick<
     | 'writeCapability'
     | 'avatarUrl'
     | 'invoiceReceiver'
+    | 'isHidden'
 > & {
     isOptimisticReport: true;
 };
diff --git a/src/libs/actions/Task.ts b/src/libs/actions/Task.ts
index fab1374ebea6..329119d688c9 100644
--- a/src/libs/actions/Task.ts
+++ b/src/libs/actions/Task.ts
@@ -650,6 +650,26 @@ function setAssigneeChatReport(chatReport: OnyxTypes.Report) {
     Onyx.merge(ONYXKEYS.TASK, {assigneeChatReport: chatReport});
 }
 
+function setNewOptimisticAssignee(assigneeLogin: string, assigneeAccountID: number) {
+    const report: ReportUtils.OptimisticChatReport = ReportUtils.buildOptimisticChatReport([assigneeAccountID]);
+
+    // When assigning a task to a new user, by default we share the task in their DM
+    // However, the DM doesn't exist yet - and will be created optimistically once the task is created
+    // We don't want to show the new DM yet, because if you select an assignee and then change the assignee, the previous DM will still be shown
+    // So here, we create it optimistically to share it with the assignee, but we have to hide it until the task is created
+    report.isHidden = true;
+    Onyx.set(`${ONYXKEYS.COLLECTION.REPORT}${report.reportID}`, report);
+
+    const optimisticPersonalDetailsListAction: OnyxTypes.PersonalDetails = {
+        accountID: assigneeAccountID,
+        avatar: allPersonalDetails?.[assigneeAccountID]?.avatar ?? UserUtils.getDefaultAvatarURL(assigneeAccountID),
+        displayName: allPersonalDetails?.[assigneeAccountID]?.displayName ?? assigneeLogin,
+        login: assigneeLogin,
+    };
+    Onyx.merge(ONYXKEYS.PERSONAL_DETAILS_LIST, {[assigneeAccountID]: optimisticPersonalDetailsListAction});
+    return {assignee: optimisticPersonalDetailsListAction, assigneeReport: report};
+}
+
 /**
  * Sets the assignee value for the task and checks for an existing chat with the assignee
  * If there is no existing chat, it creates an optimistic chat report
@@ -670,26 +690,7 @@ function setAssigneeValue(
         }
         // If chat report is still not found we need to build new optimistic chat report
         if (!report) {
-            report = ReportUtils.buildOptimisticChatReport([assigneeAccountID]);
-            report.isOptimisticReport = true;
-
-            // When assigning a task to a new user, by default we share the task in their DM
-            // However, the DM doesn't exist yet - and will be created optimistically once the task is created
-            // We don't want to show the new DM yet, because if you select an assignee and then change the assignee, the previous DM will still be shown
-            // So here, we create it optimistically to share it with the assignee, but we have to hide it until the task is created
-            if (report) {
-                report.isHidden = true;
-            }
-            Onyx.set(`${ONYXKEYS.COLLECTION.REPORT}${report.reportID}`, report);
-
-            // If this is an optimistic report, we likely don't have their personal details yet so we set it here optimistically as well
-            const optimisticPersonalDetailsListAction = {
-                accountID: assigneeAccountID,
-                avatar: allPersonalDetails?.[assigneeAccountID]?.avatar ?? UserUtils.getDefaultAvatarURL(assigneeAccountID),
-                displayName: allPersonalDetails?.[assigneeAccountID]?.displayName ?? assigneeEmail,
-                login: assigneeEmail,
-            };
-            Onyx.merge(ONYXKEYS.PERSONAL_DETAILS_LIST, {[assigneeAccountID]: optimisticPersonalDetailsListAction});
+            report = setNewOptimisticAssignee(assigneeEmail, assigneeAccountID).assigneeReport;
         }
 
         // The optimistic field may not exist in the existing report and it can be overridden by the optimistic field of previous report data when merging the assignee chat report
@@ -1051,6 +1052,7 @@ export {
     getTaskAssigneeAccountID,
     clearTaskErrors,
     canModifyTask,
+    setNewOptimisticAssignee,
 };
 
 export type {PolicyValue, Assignee, ShareDestination};
diff --git a/src/pages/home/report/ReportFooter.tsx b/src/pages/home/report/ReportFooter.tsx
index 9a8ca2955127..b128b83f88fc 100644
--- a/src/pages/home/report/ReportFooter.tsx
+++ b/src/pages/home/report/ReportFooter.tsx
@@ -12,6 +12,7 @@ import useNetwork from '@hooks/useNetwork';
 import useThemeStyles from '@hooks/useThemeStyles';
 import useWindowDimensions from '@hooks/useWindowDimensions';
 import * as ReportUtils from '@libs/ReportUtils';
+import * as UserUtils from '@libs/UserUtils';
 import variables from '@styles/variables';
 import * as Report from '@userActions/Report';
 import * as Task from '@userActions/Task';
@@ -110,10 +111,17 @@ function ReportFooter({
             const mentionWithDomain = ReportUtils.addDomainToShortMention(mention ?? '') ?? mention;
 
             let assignee: OnyxTypes.PersonalDetails | EmptyObject = {};
+            let assigneeChatReport;
             if (mentionWithDomain) {
                 assignee = Object.values(allPersonalDetails).find((value) => value?.login === mentionWithDomain) ?? {};
+                if (!Object.keys(assignee).length) {
+                    const assigneeAccountID = UserUtils.generateAccountID(mentionWithDomain);
+                    const optimisticDataForNewAssignee = Task.setNewOptimisticAssignee(mentionWithDomain, assigneeAccountID);
+                    assignee = optimisticDataForNewAssignee.assignee;
+                    assigneeChatReport = optimisticDataForNewAssignee.assigneeReport;
+                }
             }
-            Task.createTaskAndNavigate(report.reportID, title, '', assignee?.login ?? '', assignee.accountID, undefined, report.policyID);
+            Task.createTaskAndNavigate(report.reportID, title, '', assignee?.login ?? '', assignee.accountID, assigneeChatReport, report.policyID);
             return true;
         },
         [allPersonalDetails, report.policyID, report.reportID],