micro sd card problems

I bought a micro sd from the store that was the same kind as the one in my nano biscotte v4 and when I load the base sound banks for the nano it works fine. When I try to load a different font into said banks it's glitchy. I don't have that problem with the original sd card that came with the board. Any help would be greatly appreciated.

Make sure you did a complete full format on the board.

Make a copy of the default files and just replace the fonts with what you want and load the whole card at once.

I recommend the official SD Association formatter: https://www.sdcard.org/downloads/formatter_4/