Hello steve,
Welcome to Microsoft Community.
On this thread, I noticed that you seem to own multiple Surface Pro 9s, right? If you have now noticed that all the USB sticks that have been plugged into the Surface Pro 9 are not working properly, then the advice I can offer is:
- Hand over all faulty USB flash drives to the corresponding technical support team to check and confirm the status of the USB flash drive and whether it involves complete hardware damage.
- Immediately stop using all Surface Pro 9s you own and send them all to the Surface Technical support team for inspection. I can direct you to the right way to connect with Surface Live Support, who can help you create a service order: Open the Surface App (usually built into your Surface device, or you can download it from the Microsoft Store if you don't have one) and follow the procedure below:
- Click "Help and Support" and then click "Get Help".
- Briefly describe your problem in the text box, such as "All USB sticks connected to Surface Pro 9 are corrupted", and then press Enter.
- Click "Contact Support" at the bottom.
- Select "Technical Support" and click "Confirm".
- You will see "Chat support" or "phone support" options, please contact them during working hours, you will get one-to-one support services.
In conclusion, allow me to share some of my thoughts on this issue. Because the Surface Pro 9 is only equipped with two USB-C ports, but for most USB sticks on the market, the dominant port is still USB-A, so how do you connect these USB sticks to the Surface Pro 9? Are some adapters used? Or do all USB drives directly support USB-C?
Because I need to kindly remind you here that if the adapter is not compatible with Surface, then this adapter may be the main cause of this problem, we recommend using accessories developed specifically for Surface:
Cable Matters USB-C to USB-A 3.2 Gen 1 Adapter****
If my speculation is incorrect, or if you have any information you would like to share with us, please don't hesitate to let me know.
Best Regards,
Mitchell | Microsoft Community Support Specialist