Balancer is down after stopping config servers
First: balancer is running ONLY at config server replica sets PRIMARY, never on SECONDARY.

Second: (as) your error message says that, that node where you gave rs.statatus() command is not started in replica set mode, more like maintenance mode. i.e. started without --replSet or replication.replSetName config parameter and maybe also without "sharding.clusterRole: configsvr" parameter.

You can check what where starting parameters, by just reading mongod.log file. There is (at startup) list of parameters what that mongod used when it was started.