Gokuofuin

I managed to get it to work.

So I tried another 32GB Sandisk Cruiser Blade, no joy unfortunately. Then I tried a random Sandisk Cruiser Blade 16GB I had in my bag and it worked just fine. So apparently the Sandisk Cruiser Blade 32GB is incompatible with Unraid. I say that because I was just running TrueNAS on it fine and also Ubuntu. So there we go.

Thanks all for the assist! Cheers!

So I sorted it out, it was a space " " at the end of the filename. It seems like you can create a space even though Mac and Win do not support it.
 
So I used a file manager to remove the space directly from Unraid.