System information

Geth version: 1.6.1
OS & Version: Linux

I was set two node for testing poa private network, and I added one signer in per node.
when one node(A) shutdown, another node(B) will not mining. The log said: "Signed recently, must wait for others". But when I started the one just shutdown few minuts ago, nothing to happened,
The node(B) still waiting.

I`m trying to invoke web3 api clique.propose(address, false), but nothing to happened.

Please help, how to cancel a signer. thank you.