Problem with self signed certificate on Hassbian

Configuration
1

I have latest HA 0.98.2 hassbian instance running on Pi 3b+ not exposed to internet and trying to secure the local connection following the docs Self-signed certificate for SSL/TLS .

Following the above docs, managed to configure and access HA under https with IP address of the Pi with the browser complaining about the certificate, but this is not a problem, the problem is that every time I start HA the following errors appear in the log:

Error doing job: SSL error in data received
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/asyncio/sslproto.py", line 526, in data_received
    ssldata, appdata = self._sslpipe.feed_ssldata(data)
  File "/usr/local/lib/python3.7/asyncio/sslproto.py", line 189, in feed_ssldata
    self._sslobj.do_handshake()
  File "/usr/local/lib/python3.7/ssl.py", line 763, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLError: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c:1056)

Error doing job: SSL handshake failed
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/asyncio/sslproto.py", line 625, in _on_handshake_complete
    raise handshake_exc
  File "/usr/local/lib/python3.7/asyncio/sslproto.py", line 189, in feed_ssldata
    self._sslobj.do_handshake()
  File "/usr/local/lib/python3.7/ssl.py", line 763, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLError: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c:1056)

Since I’m not planing to expose the instance to the world and only use it within my home network using Let’s Encrypt is not a option.

Can someone point me on the right direction and the steps to configure secure connection with self signed certificate. Thanks in advance!