Gold and silver price gaps across markets. Why isn’t arbitrage closing these?

I was scrolling earlier and noticed something that doesn’t really make sense to me. Gold is trading about $280 higher in Mumbai than in NYC, and silver roughly $13 higher in Hong Kong than London. In theory, arbitrage should wipe out gaps like this almost instantly, but these differences seem to be sticking around. Is this just taxes, delivery and FX issues, or does it point to liquidity or settlement constraints that are messing with normal arbitrage?

Sources: Blossom Social