Can't fetch nearest block when i use arbitrum network

when i use https://rinkeby.arbitrum.io/rpc to fetch data, getBlockNumber() is 5783690 for example, but there is 5783631 when i use infura url, who can tell me why, there are lots of delay?

hi @trading_game, are you still seeing the delay ? The rpc is pretty consistent with what I see on arbiscan.