I would say you just have a bad card. 64GB cards are suppose to be supported by the OT. The fact that you got it working again sounds like the card relocated some bad blocks while it was plugged into the Mac.
When ever I get any new storage (hard disk or flash) I do a few full writes to the whole drive first with a Linux tool called dd. First I zero it out, then write random data or a repeating pattern of data, then zero it out again. After each pass I look at the drive’s SMART data to see if any blocks are being reassigned. Some being reassigned isn’t necessarily an issue, but if I see a large amount (100’s to thousands) being reassigned each pass then I would RMA the drive.
Especially on the cheap end, way too much storage is DOA right out of the factory.