Its the problem with cheap US stuff in general!

You can't properly weld cast stainless, especially low quality castings, they put high silicone content in to improve castability.

This lowers the corrosion resistance and has to be combated by increasing the nickel or the carbon content.

This has the knock on effect of making the stainless more magentic and weird to weld.

( I think I got that right, so long since I did this stuff)

Generally you get what you pay for!