Recently updated primary domain, now having issue with checkout connection

Hi!

I recently updated our primary domain from BollaKills.com (now 3rd) to BollaCo.com (current primary)

Was able to update everything but as I was doing some tests, I noticed that when I add an item and checkout on the new BollaCo.com, it goes empty and once I refresh it goes to BollaKill.com and that is the only way for customers to checkout.

Is there a plugin or navigation issue I’m not aware of?

Any suggestion are greatly appreciated!!!

Thank you