Harley Benton Parts Hollowbody Tailpiece

I bought this to replace the flimsy looking tailpiece on a Richwood Gypsy jazz Maccaferri replica.
Upon receipt, I was delighted with the substantial appearance and the quality of finish, all seemed well when I first fitted it with the strings sitting nicely in the well cast slots:however I have now been obliged to remove it and refit the original as the tailpiece has developed an upward curve which can only be explained by its response to the string tension.
I don't use heavy guage flatwound strings and I am very surprised and disappointed that the product is not fit for purpose, as it certainly looks very smart.