Database size is not important. Given your SQL Server can keep up in terms of IOPS, memory/CPU, and your backup/restore times are acceptable, you'll be fine with >200GB.
You can watch the perf counter "\Web Service(_Total)\Current Connections".
Modify your hosts file on your client to hit that single FE just to verify it is functional and accepting connections.
However, load balancing strategy is up to the load balancer. That would be the first thing to look at. Perhaps the FE was removed from the load balancing configuration, etc.