How to format a SD-card for I86HDML Plus?

Hello,

I have a 32GB (SDHC Class 10) in my Onyx Boox what contents nearly 8000 PDF Books.
The SD-card is formatted with Fat32 in WIN10. The PDF-books I have stored onto the card when the SD-card was inserted in the Boox and this device was connected with an USB-cable to the PC.

Unfortunately each time, I switch-on the Boox, the message appears "SD-Card - Checking for errors" what needs half an hour to get finally access to my reader.

If I open the Bibliothek after that waiting time, it scans all books the reader contents in the internal memory (other formats) as well as in the SD-card(all PDF that I own), what are 12500 Books over all. This needs 15 to 20mins more.
Then "Loading" is displayed, what needs more useless time.

When I select "Storage" it scanns also all books - same, if I open the Bibliothek again. Each time, I open one of this both, I have this waiting time.

How to avoid this timeconsuming steps?

Is there a way to format the SD-Card directly in the Boox - perhaps something went wrong when formatting this via USB?

Happy easter @all