If your Host Server or something else on your site (another plugin or theme) is blocking communication to the AITpro API Server then you will not see the BPS Pro upgrade notification link on the WordPress Plugins page.
That login problem to the Secure Download area occurs when you have something installed in your Browser or on your computer that breaks the redirect into the Secure Download area.
Try a different Browser or turn off all extensions or add-ons in your Browser or temporarily turn off whatever is installed on your computer that is causing the problem.