also posted on reddit, reference: https://www.reddit.com/r/capacitor/comments/1kjeg3z/capacitor_revenuecat_ios_payment_sheet_wont_open/

so this is what i can see in the xcode logs after purchase tap, not sure if its related

okay turns out the issue was having purchases-js and purchases-capicator in the same svelte component, even if the actual calls were guarded by platform checks, splitting into platform specific components solved it!