There are three ways you can try to fix the SanDisk Extreme Pro not mounting on Mac issue. First, use a USB adapter to connect your SSD with your Mac. Second, go to System Preferences to adjust external accessories settings. Third, either wait for the next upgrade patch or downgrade your current macOS.
Option 1: Use a USB adapter.
Many users reported that their external SSDs failed to mount on Mac via the original Thunderbolt ports. Luckily, when they switch to using a USB port adapter for connection, the external SSD starts to work normally.
Option 2. Allow external accessories to connect to your Mac.
This trick is discovered by Mac users on the forum. The latest macOS Ventura has one hidden setting that controls all accessories connections with your Mac. To be more specific, follow the steps below to enable Mac to recognize your SSD.
Step 1. Click on the Apple logo at the top-left corner and go to System Preferences.
Step 2. In the macOS setting panel, choose Privacy & Security.
Step 3. Under Security, you should see an option 'Allow accessories to connect'. Make sure to choose Always as the default setting.
If unfortunately, your external SSD is not mounting on Mac still, check the last solution.
Option 3. Upgrade or downgrade the current macOS.
Truth be told, the biggest possible culprit is the system itself. There are a great number of disk-related problems happening every year Apple issues a new macOS release. In this case, you can choose to wait for the next system upgrade. Hopefully, minor issues will be fixed. Or, you can manually downgrade the macOS.