Need help on pro site pricing table As soon as you can please.

Hello,
Im seeing some strange behaviour on pro site. here's what's happening. currently the project is being developed, so i have a site name ecom.thesitename.com that is on plan STARTER so i was trying to upgrade it to a higher or lower plan. When i click on Pro Upgrade button it redirects me to the pricing tables where im suppose to select a plan and then click the paypal button, what happened after i click the paypal button, im redirected to an other pro site pricing table where i have to re-select a PLAN again, so i did just that and click the Paypal button, and nothing happen after that im just keep on redirecting to another pro site pricing but this time at the url instead of thesitename.com/pro-site/?bid=3 im seeing thesitename.com/pro-site/.

I switch the theme back to twenty-fifteen and still getting the samething
NB. Support is already granted.
Please see the attachment.

Thanks for your time.