Does not default to USD on Paypal checkout then website refreshes constantly

Hi
I am trying to setup the plugon for the first time but it is not working as it should…
I set the default currenty to USD which is the same as my Paypal account, when I set the currency to seomthing that paypal does not support, I get the error “Error processing checkout”
This happens even though the checkout page is showing USD correctly

And to make things worse on mobile phone the website keeps on refreshing constantly until I use incognito mode.

My website URL is https://khototart.com/test