UNUSUAL plugin-bcli: bitcoin-cli -rpcuser=... -rpcpassword=... getblock 0000000000000000000cbce4fc71b5487ab1e5df056ac392877defc52771657c 0 exited with status 1 prints every second to the lightning.log
That implies that blocks are being pruned that it still needs. Might be an off-by-one issue. Can you tell me the block height of your lightning node, and the rescan parameter?
UNUSUAL plugin-bcli: bitcoin-cli -rpcuser=... -rpcpassword=... getblock 0000000000000000000cbce4fc71b5487ab1e5df056ac392877defc52771657c 0 exited with status 1
prints every second to the lightning.log