Body
Apple introduced a change in macOS 26 Tahoe that can affect network connectivity immediately after a Mac is rebooted.
After a reboot, the Mac may not establish its network connection until a user account that has previously logged into the device, or an account that was manually created on the device, signs in first.
Because the network connection is not available at the login screen, a student may be unable to sign in using their account. This can make it appear as though the Mac has no network or Wi-Fi connection.
At this time, macOS 26 Tahoe does not provide a configuration option to revert this behavior. As a temporary workaround, an authorized local account can be used to initialize the network connection.
What You May See
When this issue occurs:
-
The Mac has been rebooted.
-
The Wi-Fi icon may not appear in the top-right corner of the login screen.
-
A student attempts to sign in.
-
The student is unable to log in because the Mac does not yet have an active network connection.
-
The Mac may otherwise appear to be functioning normally.
This is not necessarily an indication that the Wi-Fi hardware, network, or wireless infrastructure is down.
Account Usage
There are different local administrative accounts intended for different users:
-
tadmin — Intended for teachers/staff to use when the network workaround is required.
-
jadmin / ladmin — Intended for Technology Support / IT Department use for administrative and troubleshooting purposes.
Teachers should use the tadmin account when following the temporary network workaround described in this guide.
The jadmin/ladmin accounts should remain restricted to Technology Support / IT personnel and should not be provided to students or general staff.
Temporary Workaround for Teachers
If a student is unable to log in because the Mac does not have a network connection:
-
At the login screen, sign in using the tadmin account.
-
Allow the Mac a moment to establish its network connection.
-
Log out of the tadmin account.
-
The network connection should now become available.
-
The student can then sign in using their normal account.
Example
Mac is rebooted
↓
No Wi-Fi/network connection at login screen
↓
Student cannot sign in
↓
Teacher signs in with tadmin
↓
Log out of tadmin
↓
Network becomes available
↓
Student signs in
Why This Works
Once a user successfully signs into the Mac, macOS caches the necessary account information locally.
This allows that user to sign into the same Mac again in the future, even if the Mac has been shut down or temporarily does not have network connectivity at the login screen.
For example:
-
A student successfully signs into Mac A.
-
Their account information is cached on Mac A.
-
Mac A is later shut down.
-
The student returns and turns the Mac back on.
-
The student should be able to sign in using their cached account information.
The issue is most noticeable when a Mac has been rebooted and the user attempting to sign in has not previously been cached on that device.
Important Consideration
Until a permanent solution or change from Apple is available, unnecessary reboots should be avoided.
A reboot can cause the Mac to return to the state where the network connection is unavailable at the login screen, requiring the tadmin workaround again.
This is particularly important in environments where students use shared Macs, since a reboot may affect the next student's ability to sign in.
IT Department Troubleshooting
If the tadmin workaround does not resolve the issue, or if additional troubleshooting is required, Technology Support / IT personnel should use the appropriate jadmin or ladmin account.
These accounts are intended for IT administrative and troubleshooting purposes and should not be used by students or general staff.
Current Status
This is currently being treated as a temporary workaround rather than a permanent resolution.
The goal is to continue monitoring macOS updates and Apple's handling of this behavior and determine whether a future macOS update or configuration change provides a way to restore normal network availability at the login screen.
Until then, the tadmin account provides teachers with a method to initialize the network connection when a student cannot sign in after a reboot, while jadmin/ladmin remain available for IT troubleshooting and administrative purposes.