No Amazon Pay Meta box in the Admin view for subscriptions when HPOS is activated

[ChristianAF]

Describe the bug When HPOS is Activated, the Subscription in the admin edit view there is no Amazon Pay metabox.

To Reproduce Steps to reproduce the behavior:

1. go to WooCommerce Setting and change to HPOS
2. Go to Subscription admin view and select a subscription paid with Amazon Pay
3. check that the Amazon Pay Metabox is not present.
4. deactivate HPOS and go to the same subscrption
5. Metabox is present

Screenshots

Expected behavior Meta box should be present

Isolating the problem (mark completed items with an [x]):

• [x] I have deactivated other plugins and confirmed this bug occurs when only the extension is active.
• [x] I can reproduce this bug consistently using the steps above.