site error: WSOD on /home [add Commerce Currency Resolver]

Problem/Motivation

adding 'a bunch of things' to cart on frontpage itself. (reminder: loads into cart header)

current dev10 site has products in various states due to QA, this points out when mixing currency:
this is a wider scope, assuming one more module will ensure user-sites are successful quickly!

The website encountered an unexpected error. Try again later.

Drupal\commerce_price\Exception\CurrencyMismatchException: The provided prices have mismatched currencies: 41 CAD, 11 USD. in Drupal\commerce_price\Price->assertSameCurrency() (line 316 of modules/contrib/commerce/modules/price/src/Price.php).
Drupal\commerce_price\Price->add(Object) (Line: 465)
Drupal\commerce_order\Entity\Order->recalculateTotalPrice() (Line: 308)

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes