The product details add purchase button occasionally appears unavailable

Same link. The product details add purchase button occasionally appears unavailable, but the refresh is fine. Is it a problem with Shopify.

@user4043 can you add a link to your store?

ok~

This is my store link: Meraki Espresso Coffee Machine

Or open this link Meraki Espresso Machine ;

Then click to switch types.

You want to reproduce, close the incognito browser and reopen it, then switch the type again, and you can reproduce it every time. But after refreshing, this problem will no longer occur.