Reporting settings is not working properly

Hello,

I have installed your plugin “WP Statistics” on my WP website but there is a problem with your plugin which is the reporting settings is not working !!

I have selected the send reports and chose once weekly, but still your plugin is sending daily reports !

I tried also to select send reports once a week but still your plugin is sending daily reports !

I tried all possible ways to have your plugin send reports to my Email only one time per week but still your plugin is sending daily reports !

whats wrong here why your plugin is having this issue?!

Please advise,
Thank you