Error HA - Tak exception

Hi guys, some weel i have this error in the log, : what your suggest me for go to in deep analy

2021-05-23 10:27:17 ERROR (MainThread) [homeassistant] Error doing job: 

Task exception was never retrieved Traceback (most recent call last):
File "/usr/src/homeassistant/homeassistant/components/alexa/state_report.py", line 93, in async_entity_state_listener

if not checker.async_is_significant_change
(File "/usr/src/homeassistant/homeassistant/helpers/significant_change.py", line 175, in async_is_significant_change
result = check_significantly_changed(File "/usr/src/homeassistant/homeassistant/components/sensor/significant_change.py", line 37, 
in async_check_significant_change old_value = float(old_state)

ValueError: could not convert string to float: 'None'