How to decrease max_connection by update --patch pgParameters in cluster

Hi, I am a newbie who uses the stolon. Recently I want to decrease the max connections. However, it fails. The command is as follows.
when I want to increase the max connection, it worked.
docker exec -it stolon-proxy stolonctl --cluster-name=stolon-cluster update --patch '{ "pgParameters" : {"max_connections" : "300", "shared_buffers" : "384MB" } }'

After a while, I want to decrease the connection to 100. Then the slave fails.
docker exec -it stolon-proxy stolonctl --cluster-name=stolon-cluster update --patch '{ "pgParameters" : {"max_connections" : "100", "shared_buffers" : "128MB" } }'
The slave stolon keeper have the following error:

hot standby is not possible because max_connections = 100 is a lower setting than on the master server (its value was 300)

but both the master and all the slave’s max connection is already 100 now.

Let me know if you have any ideas.
And if you figure out that someone ever asked the question. let me know. And I will close the topic. Thanks

en… I manage to fix this problem. The step to decrease connections.
1, docker exec -it stolon-proxy stolonctl --cluster-name=stolon-cluster(replace by your cluster name) update --patch ‘{ “pgParameters” : {“max_connections” : “100”, “shared_buffers” : “384MB” } }’
2, restart master stolon-keeper
3, pay attention!!! wait for about 5 min (decided by wal log sent period)
4, restart other slave stolon-keeper