Hi JustinBradford,
Thank you for reaching Microsoft Community. I'm sorry to hear about the issue on your Surface Pro 6 after the upgrade to Windows 11.
Does this happen on multiple SD cards?
May I know what are the make and models of the SD cards you have tried?
Does the SD card shows an error in Device Manager? If yes, please provide us with the error code and message.
Please try these steps below then see if the issue persist:
1: Run Surface Diagnostic Toolkit
See: Fix common Surface problems using the Surface Diagnostic Toolkit (microsoft.com)
2: Check for Windows Update
Go to Windows Settings > Update & Security and select Check for updates
Make sure all updates need are installed including Optional updates
3: Run System File Checker Tool
See: Using System File Checker in Windows (microsoft.com)
4: Run the Hardware troubleshooter
Go to Windows Settings > System > Troubleshoot
Select More troubleshooter
Click the Run option next to Hardware and devices
5: Check if the SD card has a drive letter assigned
Open Disk Management
Check if the SD card shows up (should show up as a Removable device)
If it does, check if it has a drive letter assigned
Right-click on the SD card then choose Change Drive Letter and Paths
Click Add then choose one of the available letters then hit OK (if it has a drive already, try changing the letter)
Close Disk Management then restart the Surface
Hope this helps.