Salespanel captures leads whenever they provide their email on your website. Therefore, it is possible for Salespanel to capture an already existing customer who has visited after you have installed the tracking code.
To avoid this, you can disable lead capture from pages on your website where revisiting customers are acquired from. The login page for example.
To blacklist URLs, navigate to the tracking code section and click on Advanced Tracking. Add the URLs you want to block lead capture from and click on Save.
Once done, Salespanel will not capture any new contact from these URLs.