It depends what you mean. Is the warranty scan giving errors and not scanning/refreshing the information? Or is it being scanned correctly but the information is incorrect?
You can use the built-in report "Assets: Warranty scanning errors" to check for errors.
Currently there is a known issue with non enterprise HP products. Lansweeper uses an API and several URLs to retrieve warranty information of HP assets. The API is used for HP Enterprise products like servers, while the additional URLs are for normal HP products like workstations. Unfortunately we discovered that the HP URLs we use for warranty checks are giving errors due to a change HP made to them. When HP makes unannounced changes to the way their warranty URLs or API works this can cause issues.
If the warranty is being scanned successfully (without errors) then you can do a manual warranty check with HP and compare it with Lansweeper. If HP gives incorrect information, so will Lansweeper.