Initiate Checkout Data Layer Not Populating in GTM

I’m using WordPress + Woocommerce. I’m stuck with an enhanced eCom conversion setup in GTM — it’s regarding initiate checkout event. The Data Layer is not populating the items (says “null”) whenever a checkout is initiated. This data is only populated once the purchase event has been triggered. Any experts available to help?

Here is the screenshot of the issue: https://imgur.com/z2ibMJG

I must add, add_to_cart is picking all the details… but initiate checkout is not picking any details in the data layer. This is super weird. And what’s weirder is that initiate checkout data layer also gets populated as soon as purchase event has been completed.

Here is the screenshot of initiate checkout once the purchase event has been completed: https://imgur.com/zswzVkG

Any help will be super appreciated!

P.S. Begin_checkout data layer never populates even after purchase event. But the initiate checkout event page starts showing all the data after the purchase event (but doesn’t do it before the purchase either).

The page I need help with: [log in to see the link]