A recent change? Maybe Sig customer service could explain. I replaced mine at 3000 rounds but had no issues with it.
A friends son in law is a rep for Sig. He called me once, said his mother in law ask him a couple questions about handguns that made sense. Knowing they came from someone else, he ask her about it and was referred to me. I'll try to remember to call him and see if he knows anything about it.