Hi there! I see you're encountering 401 errors in the MultiTab app, and you mentioned that multiple users you know might be affected, raising concern about a possible hacking issue. I want to understand a bit more first to help you effectively:

- When exactly do you see the 401 errors? For example, does it happen during login, while using specific features, or when opening the app in multiple tabs or devices?
- Are these errors affecting just your device or multiple devices and users broadly?
- Have you or the users noticed any suspicious activity like unknown logins or password changes?
- Have any error messages included details like "Unauthorized" or "Invalid token"?

A 401 Unauthorized error typically means that the app or server is rejecting access due to invalid or missing authentication credentials. This can happen due to expired login tokens, account permissions, or sometimes server issues—not necessarily hacking.

Here’s a step-by-step plan to check and potentially fix this:

1. Log Out and Log Back In: Try logging out completely and then signing back in. This refreshes session tokens which often resolve 401 errors.

2. Clear App Cache (if possible): On iPhone, you can try uninstalling and reinstalling the MultiTab app to clear cache and stored data that might be corrupted.

3. Update the App: Make sure you and others are using the latest version of the MultiTab app, as updates often fix authentication bugs.

4. Check for Multiple Sessions: Some apps block multiple simultaneous logins from the same account or device. If users are logged into multiple devices or browser tabs, advise them to sign out everywhere and log in again in just one place.

5. Password Reset: If you suspect accounts may have been compromised, a password reset is good practice. It also invalidates existing sessions that use older credentials.

6. Check Network and Permissions: Since you're on iOS 18.6, ensure your internet connection is stable and no VPN or proxy is interfering with app authentication.

7. Confirm With MultiTab Support: If 401 errors persist widely and you suspect a security breach, check if MultiTab has sent any alerts or advisories about their authentication servers or ongoing incidents.

If you’ve already done some of these steps, let me know which ones so I can suggest more advanced troubleshooting, like checking token validity or inspecting account settings. Does your MultiTab app allow access to account activity logs or login histories?

Let me know how you want to proceed! Are you seeing these errors on specific users' devices or across your whole team?