You still ought to try increasing the distance between the pickup and the strings. 5-6 mm may be too close for that pickup.
If that doesn't work, if I were you, I'd get it repaired before putting in a substitute.
As Rob said, that Artec is a mudbucker replacement. Don't buy it unless you're looking for mud. And if you are, IMHO better to spend the extra money and buy a used genuine Gibson mudbucker than put a cheap Korean clone in a real Gibson bass.
AFAIK the Allparts version is still made by Gotoh. Low output, tame sounding. Fine if that's what you're looking for. But neither it nor the Artec are like the TB+ original.
Curtis Novak will make you one that looks like the original and wind it to your preference but his price is over $200 US.