This is almost certainly another of the "incompatible driver" issues.
In an attempt to fix it I would try the following, in the order listed:
1. Go to Dell's support website for your specific model and see if an updated driver for the card reader exists, even if it's for Win8 instead of Win10. If so, download it, uninstall the existing driver, and update with the downloaded driver.
2. Check at the hardware manufacturer's website to see if they have an updated driver for the reader in question for Win10 (or even Win8). If so, same as step 1 afterward.
3. Uninstall the driver for the card reader then uninstall the device itself in device manager. Then do a "Scan for new hardware" and see if the driver downloaded by Windows 10 itself, based on the card reader detection, works.
I've got nothing beyond that.
Brian AKA Bri the Tech Guy (website in my user profile) - Windows 10 Home, 64-Bit, Version 1803, Build 17134
Memory is a crazy woman that hoards rags and throws away food.
~ Austin O'Malley