The “remote_addr” session value is invalid

ON the backend Store>Configurations>General>Web we have set the “Session Validation Settings” which shows these options:

Validate REMOTE_ADDR: YES

Validate HTTP_VIA: YES

Validate HTTP_X_FORWARDED_FOR: YES

Validate HTTP_USER_AGENT: YES

We are getting following errors in var/log/system.xml file.

The “remote_addr” session value is invalid. Verify and try again. [] []
The “http_user_agent” session value is invalid. Verify and try again. [] []

does anyone knows the reason behind such errors, why this is happening. how we can fix this?