Then, try reading the card again. Another way to check if your card slot functions as intended is to use a working SD card and read it using a Type C-to-SD card reader.

If your SD Card is not detected in Device Manager, it can be caused due to outdated drivers, hardware issues, etc. Use these fixes to resolve this issue.

The SD card was working normally minutes prior, but after Steam had reformatted it on SteamOS, downloads became so slow that they were basically unusable.