How to free up internal memory of BOOX device (Boox go 6)?

[AnnieQuinn]

This is my first time using an e-reader so I'm a bit clueless. I hope you can help me.

I'm using Boox go 6. The internal memory is 32GB, after the basic setup, there is still ~20GB available.

I store books on an external memory card, and there are a lot of books. When creating a library and scanning books from the memory card, I noticed that the free memory of the device is also decreasing slowly according to the number of books imported. I think the device also uses the internal memory to manage the library.

However, when I delete a few libraries, even delete the entire library, the device's memory is still not freed up.

For example: When I add 1 library, the available internal memory is ~18GB
When there are 2 libraries, ~16GB
When there are 3 libraries, ~12GB
And when I delete the entire library, the available memory is still ~12GB.

If I add a new library, it immediately drops to ~11GB or less, depending on how many books I add.