Unable to Mount / Format Smart Media Cards MacOS 10.14.4

Hey, I've got 5 x 64MB Smart Media cards which have all been formatted to work with my sampler (Boss SP303) to store samples and patterns. They work perfectly on the SP.

I should be able to read these cards on my 2014 MBP but only one of them mounts correctly so I'm able to copy over .wav samples from my Mac to the card, and then load into my SP303.

When I attempt to mount the other 4 on my Mac I get the 'The disk you inserted was not readable by the computer.. initialise / ignore / eject' prompt.

As an experiment I've tried to format these cards on my MBP - I've tried MS-DOS FAT and exFAT but I get the error message 'Generic USB SM Reader Media...process has failed...unable to write to last block of the device.'

Bummer! However, if I reformat them on the SP they work :/

To read them on the Mac I'm using a USB All-in-One Card reader via USB cable. I've tried 3 different cables to no avail. I've also tested an SD card using the card reader which mounts perfectly.

It's frustrating how 1 of the SM cards work on my MBP but the other 4 don't!

Appreciate any pointers but understand that SM cards are vintage tech.

Cheers

VP