Unfortunately sometimes the pins inside the SD Card slot can bend. This causes that the memory cards cannot be read by the console. Glady we offer replacement sockets. The sockets are taken from consoles, they are in working order, but can look a bit used. Do not believe in other offers telling you that they are new. They are not available as new items.
This slot just fits in the Nintendo Switch.
There are some skills needed to insert the Slot, we recommend to search on YouTube for a repair video.