When BSC_CLUSTER_SIZE=21 , node panic

[erick785]

when .env set BSC_CLUSTER_SIZE=21, The node will panic. However, when setting BSC_CLUSTER_SIZE=5, the node runs normally.

panic: runtime error: index out of range [0] with length 0


goroutine 4562 [running]:
github.com/ethereum/go-ethereum/consensus/parlia.(*Snapshot).apply(0xc012b9c0e0, {0xc0107a06d8, 0x1, 0x25df380?}, {0x32ec548, 0xc01057c008}, {0xc0107a06d0, 0x0, 0x1}, 0x46e2280)
	github.com/ethereum/go-ethereum/consensus/parlia/snapshot.go:355 +0x114d
github.com/ethereum/go-ethereum/consensus/parlia.(*Parlia).snapshot(0xc010500008, {0x32ec548, 0xc01057c008}, 0x127dd910?, {0x44, 0xe4, 0xbd, 0x59, 0x27, 0x90, ...}, ...)
	github.com/ethereum/go-ethereum/consensus/parlia/parlia.go:825 +0x973
github.com/ethereum/go-ethereum/consensus/parlia.(*Parlia).GetJustifiedNumberAndHash(0xc010500008, {0x32ec548, 0xc01057c008}, {0xc0107a06d0, 0x1, 0x1})
	github.com/ethereum/go-ethereum/consensus/parlia/parlia.go:2000 +0x13b
github.com/ethereum/go-ethereum/core.(*BlockChain).GetJustifiedNumber(0xc01057c008, 0xc012bee788)
	github.com/ethereum/go-ethereum/core/blockchain.go:682 +0xa4
github.com/ethereum/go-ethereum/core.(*ForkChoice).ReorgNeededWithFastFinality(0xc000a20340, 0xc012bb1188, 0xc012bee788)
	github.com/ethereum/go-ethereum/core/forkchoice.go:150 +0xd0
github.com/ethereum/go-ethereum/core.(*BlockChain).writeBlockAndSetHead(0xc01057c008, 0xc0127df290, {0xc0107a06b8, 0x1, 0x1}, {0xc0107a06c8, 0x1, 0x1}, 0xc011b48c88, 0x1)
	github.com/ethereum/go-ethereum/core/blockchain.go:1935 +0xaa
github.com/ethereum/go-ethereum/core.(*BlockChain).WriteBlockAndSetHead(0xc01057c008, 0xc0127df290, {0xc0107a06b8, 0x1, 0x1}, {0xc0107a06c8, 0x1, 0x1}, 0xc011b48c88, 0x1)
	github.com/ethereum/go-ethereum/core/blockchain.go:1928 +0x114
github.com/ethereum/go-ethereum/miner.(*worker).resultLoop(0xc001225688)
	github.com/ethereum/go-ethereum/miner/worker.go:676 +0xc74
created by github.com/ethereum/go-ethereum/miner.newWorker in goroutine 1
	github.com/ethereum/go-ethereum/miner/worker.go:309 +0x83b