Attached shows config format display. This issue doesn't occur until switching from rendered entity to add to cart as shown in attached.
On product page load under footer comes error: Missing bundle for entity type commerce_order_item
dblog shows:
Drupal\Core\Entity\EntityStorageException: Missing bundle for entity type commerce_order_item in Drupal\Core\Entity\ContentEntityStorageBase->doCreate() (line 75 of /app/web/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php) #0 /app/web/core/lib/Drupal/Core/Entity/EntityStorageBase.php(184): Drupal\Core\Entity\ContentEntityStorageBase->doCreate(Array) #1 /app/web/modules/contrib/commerce/modules/order/src/OrderItemStorage.php(23): Drupal\Core\Entity\EntityStorageBase->create(Array) #2 /app/web/modules/contrib/commerce/modules/product/src/ProductLazyBuilders.php(80): Drupal\commerce_order\OrderItemStorage->createFromPurchasableEntity(Object(Drupal\commerce_product\Entity\ProductVariation)) #3 [internal function]: Drupal\commerce_product\ProductLazyBuilders->addToCartForm('15', 'full', true, 'en') #4 /app/web/core/lib/Drupal/Core/Render/Renderer.php(358): call_user_func_array(Array, Array) #5 /app/web/core/lib/Drupal/Core/Render/Renderer.php(195): Drupal\Core\Render\Renderer->doRender(Array, true) #6 /app/web/core/lib/Drupal/Core/Render/Renderer.php(151): Drupal\Core\Render\Renderer->render(Array, true) #7 /app/web/core/lib/Drupal/Core/Render/Renderer.php(582): Drupal\Core\Render\Renderer->Drupal\Core\Render\{closure}() #8 /app/web/core/lib/Drupal/Core/Render/Renderer.php(152): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure)) #9 /app/web/core/lib/Drupal/Core/Render/Renderer.php(166): Drupal\Core\Render\Renderer->renderPlain(Array) #10 /app/web/core/modules/big_pipe/src/Render/BigPipe.php(696): Drupal\Core\Render\Renderer->renderPlaceholder('callback=commer...', Array) #11 /app/web/core/modules/big_pipe/src/Render/BigPipe.php(550): Drupal\big_pipe\Render\BigPipe->renderPlaceholder('callback=commer...', Array) #12 /app/web/core/modules/big_pipe/src/Render/BigPipe.php(305): Drupal\big_pipe\Render\BigPipe->sendPlaceholders(Array, Array, Object(Drupal\Core\Asset\AttachedAssets)) #13 /app/web/core/modules/big_pipe/src/Render/BigPipeResponse.php(112): Drupal\big_pipe\Render\BigPipe->sendContent(Object(Drupal\big_pipe\Render\BigPipeResponse)) #14 /app/vendor/symfony/http-foundation/Response.php(373): Drupal\big_pipe\Render\BigPipeResponse->sendContent() #15 /app/web/index.php(20): Symfony\Component\HttpFoundation\Response->send() #16 {main}.
I've tried various config with keeping add to cart in manage display for the entity reference field, Variations, though same error remained. I also looked to debug line 72 but all I could tell was that $this->bundleKey had value of type, and that $values[$this->bundleKey] is null.
var_dump shows from ContentEntityStorageBase.php that the array begins with: 'type' => NULL 'title' => string(4) "EZ12"
Not sure what step to take next on it.