Repeated join and leave events for Consul agent on Windows

#### Overview of the Issue

Some of our agents running Windows are having random left and join events causing a service to completely de-register and come back after about 30 seconds. The odd part is that a host will have an uppercase node name and a lower case node name. The node ID's are always different. For example this is seen in a detailed member list:

```
MNP-OSW-APP02 172.16.113.247:8301 alive acls=1,build=1.6.1:9be6dfc3,dc=tcf-dc1-prd,id=96c6c19f-706c-0040-9ac3-6a941bd9194b,role=node,segment=,vsn=2,vsn_max=3,vsn_min=2
MNP-OSW-WEB01 172.16.34.25:8301 alive acls=1,build=1.6.1:9be6dfc3,dc=tcf-dc1-prd,id=67ce4930-25a1-2372-6ca0-e6e9b1f3af93,role=node,segment=,vsn=2,vsn_max=3,vsn_min=2
mnp-osw-app02 172.16.113.247:8301 left acls=1,build=1.6.1:9be6dfc3,dc=tcf-dc1-prd,id=77a3b884-d38b-597a-4054-fcb3d77097cc,role=node,segment=,vsn=2,vsn_max=3,vsn_min=2
mnp-osw-web01 172.16.34.25:8301 left acls=1,build=1.6.1:9be6dfc3,dc=tcf-dc1-prd,id=b745b322-aa18-2f04-5cc2-fcb497903cc1,role=node,segment=,vsn=2,vsn_max=3,vsn_min=2
```

The uppercase node is the correct one. The Serf Health Status will always pass but our service wmi-exporter will disappear and reappear along with it's health check.

We are running 3 Consul servers on CentOS 7 with agents running varying distros of Linux and versions of Windows.

#### Reproduction Steps

Reproduction seems random but only happens on Windows servers. Setting the `node_name` in the configuration seems to help sometimes but not always. We have tried completely wiping the installation of Consul, force-leave with prune, and starting Consul on the node with some success as well but it most cases it will happen again some time later.

### Consul info for both Client and Server

Client info

```
agent:
check_monitors = 0
check_ttls = 0
checks = 1
services = 1
build:
prerelease =
revision = 9be6dfc3
version = 1.6.1
consul:
acl = enabled
known_servers = 3
server = false
runtime:
arch = amd64
cpu_count = 4
goroutines = 47
max_procs = 4
os = windows
version = go1.12.1
serf_lan:
coordinate_resets = 0
encrypted = true
event_queue = 0
event_time = 36
failed = 53
health_score = 0
intent_queue = 0
left = 24
member_time = 163054
members = 2635
query_queue = 0
query_time = 918
```

Server info

```
agent:
check_monitors = 0
check_ttls = 0
checks = 0
services = 2
build:
prerelease =
revision = 1200f25e
version = 1.6.2
consul:
acl = enabled
bootstrap = false
known_datacenters = 1
leader = true
leader_addr = 172.16.34.161:8300
server = true
raft:
applied_index = 23259753
commit_index = 23259753
fsm_pending = 0
last_contact = 0
last_log_index = 23259753
last_log_term = 375
last_snapshot_index = 23258826
last_snapshot_term = 375
latest_configuration = [{Suffrage:Voter ID:dc94ced3-c768-b8ed-4af4-78d71392433f Address:172.16.34.161:8300} {Suffrage:Voter ID:08ec87b0-60f5-0d2d-26f1-ed07c1d8a782 Address:172.16.34.162:8300} {Suffrage:Voter ID:908ee8fc-721d-1938-1378-40c3080714a8 Address:172.16.34.160:8300}]
latest_configuration_index = 20229906
num_peers = 2
protocol_version = 3
protocol_version_max = 3
protocol_version_min = 0
snapshot_version_max = 1
snapshot_version_min = 0
state = Leader
term = 375
runtime:
arch = amd64
cpu_count = 2
goroutines = 6479
max_procs = 2
os = linux
version = go1.12.13
serf_lan:
coordinate_resets = 0
encrypted = true
event_queue = 0
event_time = 36
failed = 181
health_score = 0
intent_queue = 0
left = 19
member_time = 162973
members = 2759
query_queue = 0
query_time = 918
serf_wan:
coordinate_resets = 0
encrypted = true
event_queue = 0
event_time = 1
failed = 0
health_score = 0
intent_queue = 0
left = 0
member_time = 95
members = 3
query_queue = 0
query_time = 1
```

### Operating system and Environment details

Server:
- CentOS 7
- version 1.6.2

```json
{
"data_dir": "/var/lib/consul",
"client_addr": "0.0.0.0",
"bind_addr": "0.0.0.0",
"node_name": "mnp-dist-app11.corp.tcf.biz",
"advertise_addr": "172.16.34.161",
"datacenter": "tcf-dc1-prd",
"primary_datacenter": "tcf-dc1-prd",
"telemetry": {
"prometheus_retention_time": "30s",
"disable_hostname": true
},
"node_meta": {
"team": "system-insights",
"environment": "prod"
},
"performance": {
"raft_multiplier": 5
},
"dns_config": {
"allow_stale": true
},
"discovery_max_stale": "5s",
"retry_join": [
"mnp-dist-app12.corp.tcf.biz","mnp-dist-app11.corp.tcf.biz","mnp-dist-app10.corp.tcf.biz"
],
"encrypt": "...",
"acl": {
"enabled": true,
"default_policy": "deny",
"down_policy": "extend-cache",
"tokens": {
"default": "...",
"master": "...",
"agent": ".."
}
}
}
```

Agent:
- Windows Server 2016
- version 1.6.1

```json
{
"advertise_addr": "{{ GetDefaultInterfaces | exclude \"type\" \"IPv6\" | limit 1 | attr \"address\" }}",
"node_name": "MNP-OSW-APP02",
"data_dir": "C:/insights-client/consul/data",
"log_file": "C:/insights-client/consul/logs/consul.log",
"log_level": "err",
"log_rotate_duration": "24h",
"log_rotate_max_files": 7,
"datacenter": "tcf-dc1-prd",
"primary_datacenter": "tcf-dc1-prd",
"client_addr": "127.0.0.1",
"bind_addr": "0.0.0.0",
"disable_update_check": true,
"rejoin_after_leave": true,
"ports": {
"http": 8500,
"dns": 8600,
"serf_lan": 8301,
"serf_wan": 8302
},
"retry_join": [
"mnp-dist-app12.corp.tcf.biz","mnp-dist-app11.corp.tcf.biz","mnp-dist-app10.corp.tcf.biz"
],
"encrypt": "...",
"acl": {
"enabled": true,
"default_policy": "deny",
"down_policy": "extend-cache",
"tokens": {
"default": "...",
"agent": "..."
}
}
}

```

### Log Fragments

Server leader:

```
2020/02/13 11:22:29 [INFO] consul: member 'MNP-OSW-APP02' joined, marking health alive
2020/02/13 12:00:42 [INFO] serf: EventMemberJoin: mnp-osw-app02 172.16.113.247
2020/02/13 12:00:56 [INFO] memberlist: Marking mnp-osw-app02 as failed, suspect timeout reached (2 peer confirmations)
2020/02/13 12:00:56 [INFO] serf: EventMemberFailed: mnp-osw-app02 172.16.113.247
2020/02/13 12:00:56 [INFO] consul: member 'mnp-osw-app02' failed, marking health critical
2020/02/13 12:01:31 [INFO] consul: member 'MNP-OSW-APP02' joined, marking health alive
2020/02/13 12:01:31 [INFO] consul: member 'mnp-osw-app02' failed, marking health critical
2020/02/13 12:02:29 [INFO] consul: member 'MNP-OSW-APP02' joined, marking health alive
2020/02/13 12:02:29 [INFO] consul: member 'mnp-osw-app02' failed, marking health critical
2020/02/13 12:03:30 [INFO] consul: member 'MNP-OSW-APP02' joined, marking health alive
2020/02/13 12:03:30 [INFO] consul: member 'mnp-osw-app02' failed, marking health critical
2020/02/13 12:04:31 [INFO] consul: member 'MNP-OSW-APP02' joined, marking health alive
2020/02/13 12:04:31 [INFO] consul: member 'mnp-osw-app02' failed, marking health critical
```