"ConnectionResetError" in plot create/export as png

Bokeh 2.1.1
Python 3.8.3
geckodriver 0.26.0
Mozilla Firefox 78.0.1
Puppy Linux 64-bit

I am seeing the following intermittent error when running a simple set of bar plots. I can’t reproduce it to order.

Traceback (most recent call last):
File “/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py”, line 670, in urlopen
httplib_response = self._make_request(
File “/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py”, line 426, in _make_request
six.raise_from(e, None)
File “”, line 3, in raise_from
File “/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py”, line 421, in _make_request
httplib_response = conn.getresponse()
File “/usr/local/lib/python3.8/http/client.py”, line 1332, in getresponse
File “/usr/local/lib/python3.8/http/client.py”, line 303, in begin
version, status, reason = self._read_status()
File “/usr/local/lib/python3.8/http/client.py”, line 264, in _read_status
line = str(self.fp.readline(_MAXLINE + 1), “iso-8859-1”)
File “/usr/local/lib/python3.8/socket.py”, line 669, in readinto
return self._sock.recv_into(b)
ConnectionResetError: [Errno 104] Connection reset by peer

The code generating this iterates over dictionary of up to 28 keys, for each key, calls a function to create a vertical bar chart, exporting the plot as a png using export_png().

I literally have no idea where to start in bottoming this, I’m not a professional programmer & Linux sockets are way out of my skillset.