my Chuwi Hi8 Pro didn’t read micro sd cards. I first thought it was a driver problem until i found out it does read micro sd cards when i push and hold it deeply in the slot. As soon as i released the pressure, the sd card was unmounted.
When i opened the tablet i found the problem. There was a tiny gap between the metal casing and the sd-detect pin, when the sd card was inserted.
After carefully bending the casing-tab a little bit inwards, the problem was fixed an the tablet reads sd cards properly.