Just to be clear, the weld is breaking off the joint? I pointed to it on the picture. Is that correct?
If that is the case then the only thing I can suspect is an inferior product because that is not something that would normally fail.
Also, if I am understanding correctly, you replaced this as it was broken and then it happened again to the replacement part? One thing to make sure is they are not getting installed upside down. It looks like it would not fit if they put them on wrong but anything is possible. The stud should be facing up just like you have it laying on the floor and as seen in the other picture.
Images (Click to make bigger)
Friday, October 2nd, 2020 AT 6:11 PM