Please, in simple terms can someone help me out here without suggesting using Warpinator or similar?

I have a 32GB MicroSD card that can be seen and used by my Windows PC. I’ve been putting big files on it, then putting it in my Steam Deck to put them where needed in Desktop mode. It’s worked great but I need to move files that are bugger than 32GB so got myself a new Micro SD card.

However I can’t figure out what the hell I did to make it so my 32GB Micro SD card can be seen and interacted with on both devices It looks like the format of the 32GB card is Fuseblk, but googling what this means or how to format my new card like this is leading me nowhere. There must be a way to do this, as I have already done it?! My new card is a 128GB Sandisk Extreme if that’s any help.