Flash drives do not show up on Macbook Pro

Hi there, since you mentioned that the Seagate external hard drive works well on your macOS computer, I confirm the computer driver and OS is functional. You can head to Disk Utility to select Show All Devices to see if it shows on your Mac.

Step 1: Connect your flash drive to your computer and launch Disk Utility.

Step 2: Click the downward arrow on top of the View button and select Show All Devices.

Step 3: Check if the flash drive appears.

Meanwhile, I am not sure what "any" means. Does it mean that you have tried all your flash drives on your Mac computer? If does, I feel sorry to tell you that your flash drives might be failed and you can buy a new one with good quality.