IndexError: list index out of range

[fencepost-error]

When I poll a device the code runs for a minute or two and then starts throwing 'IndexError: list index out of range' errors:

ERROR    Failed to poll modbus device, attempting to reconnect: list index out of range
Traceback (most recent call last):
  File "/home/odroid/.local/lib/python3.10/site-packages/modbus4mqtt/modbus4mqtt.py", line 100, in poll
    self._mb.poll()
  File "/home/odroid/.local/lib/python3.10/site-packages/modbus4mqtt/modbus_interface.py", line 134, in poll
    self._values[table][key] = values[x]
IndexError: list index out of range

I've had a quick look into the code, but see my previous post about lack of familiarity with Python.