I’ve noticed an issue where the Web Report Overview is showing just over 4000 pc’s, but the console only shows around 3500.
I’ve run the batch commands to delete duplicates and deleted entries from the SQL database. However this does not seem to make any difference to the web report figure.
Earlier versions of the “DeletedComputerRemover” tool that removes computers from the database had an issue where it would sometimes lead to cache corruption and the issue you are referring to might be caused by web reports cache corruption.
Try rebuilding the cache as Stacy suggests, and hopefully that will help.