Herm Sprenger bit question

Awhile back I bought a sprenger loose ring snaffle for my mare on eBay, I had been wanting to try a sprenger bit but I didn’t want to spend a bunch of money only to have her not like it. When I recieved the bit I noticed that there was a crack right in the center of the joint on the bit. The crack was small and didn’t seem like it would cause a problem so I decided to go ahead and use the bit. I have been using the bit for quite awhile now with no issues, the crack has not gotten any worse, and the horse loves it. I then decided to try to find another sprenger bit on eBay, this time I got a loose ring with the shaped Balkenhol mouthpiece. I was really excited at the deal I got on this bit, however when it arrived in the mail this bit was cracked in the same place as the other one. Am I just THAT unlucky that I got 2 cracked bits? or is this an issue with Herm Sprenger bits? I’m trying to decide if I should ask for a refund from the seller on this bit, the ad said the bit was in great shape with a few teeth marks, it said nothing about a cracked mouthpiece. Has anyone else experienced this problem with these bits?

I once reached out to Herm Sprenger about this. They said it was the bit design_ something about how the metals were heated and fused. Now I have about 8 Sprenger snaffles and it is only visible on 2. I was suspicious of their answer, but I have never had any problems.

They use quite a lot of copper in the Aurigan 98% and copper is a soft metal that pits and corrodes. If it is a crack keep it clean after each use.

Thanks for the replies, I feel a bit better using these bits now. The horse certainly likes them!