This is not a SWAP, even if you give this partition a name 'SWAP': "Linux just reserves a separate empty partition for swap space". Empty = it has no formatting. But as I explained above, in Enigma2, given it is a Linux based system, I use EXT4 and create a SWAP file on EXT4.
What you call SWAP you actually format in FAT32 and that by definition is not SWAP. See above.