Hi @Sharon Slinger
If you're using mobile data, try switching to Wi-Fi and vice-versa. Make sure Airplane mode is off.
Make sure you're using the latest version of Authenticator - Microsoft does not support any app versions more than 12 months old. Tap Settings and make sure App updates is turned on. Get the latest.
Tap Settings and select Turn off battery optimization for better sync performance.
Tap Settings > Notification Settings and make sure Show notifications is turned on.
Make sure your device is up to date, and that any other security apps (such as Microsoft Defender and Intune Company Portal) are also up to date. Make sure the device's Date & time are correct too.
If you're using VPN, try disconnecting to see if the issue persists.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.