[BUG] Windows minion master_alive_interval breaks communication when master_type is str

[WayneSherman]

Tested Systems Info
Salt master v3003 running on Ubuntu 20.04.2 LTS (kernel 5.4.0-70-generic)
Salt minion v3003 running on Win10 Pro 20H2 (build 19042.870)

Description
master_alive_interval breaks communication between the master and minion on Windows.

Setup

# Windows Minion Config
master:
  - xxx.xxx.xxx.xxx
master_port: xxxxx
master_type: str
master_alive_interval: 30

Steps to Reproduce the behavior

1. Run the minion
2. On the master start pinging the minion:
   while sleep 2; do salt 'minion-name' test.ping; done
3. pings are successful for about 30 seconds until the alive_interval is triggered. After that all pings fail.

Expected behavior
test.ping from the master should continue to work after master_alive is triggered.

minion log

[DEBUG   ] schedule.handle_func: adding this job to the jobcache with data {'id': 'DESKTOP-XXXXX', 'fun': 'status.master', 'fun_args': 
[{'master': 'xxx.xxx.xxx.xxx', 'connected': True}], 'schedule': '__master_alive_xxx.xxx.xxx.xxx', 'jid': '20210412033406947641', 'pid': 2144}
[DEBUG   ] LazyLoaded config.get
[DEBUG   ] SaltEvent PUB socket URI: 4510
[DEBUG   ] SaltEvent PULL socket URI: 4511
[DEBUG   ] Sending event: tag = __master_disconnected; data = {'master': 'xxx.xxx.xxx.xxx', '_stamp': '2021-04-12T03:34:08.619691'}
[DEBUG   ] Closing IPCMessageClient instance
[DEBUG   ] schedule.handle_func: Removing c:\salt\var\cache\salt\minion\proc\20210412033406947641
[DEBUG   ] Minion of 'xxx.xxx.xxx.xxx' is handling event tag '__master_disconnected'
[INFO    ] Connection to master xxx.xxx.xxx.xxx lost

[xeacott]

And this as well @WayneSherman I'll ask my team. I'm going to think that the other issue and this one are related to some degree