When a new item is created from Boomi, it gets the website assigned to the store
from the url, but when the next call comes for the other site, it does not
assign the website to it.

i.e.
first call to /rest/drcomfort_b2b_en/V1/products will create sku and add to B2B
when second call comes right after for /rest/V1/products it does not assign to B2C store

diff --git a/vendor/magento/module-catalog/Model/ProductRepository.php b/vendor/magento/module-catalog/Model/ProductRepository.php
--- a/vendor/magento/module-catalog/Model/ProductRepository.php
+++ b/vendor/magento/module-catalog/Model/ProductRepository.php
@@ -397,6 +397,15 @@
             $product->setData($key, $value);
         }

+        $requestUri = $_SERVER['REQUEST_URI'] ?? '';
+        if ($requestUri === '/rest/V1/products' || $requestUri === '/rest/drcomfort_b2b_en/V1/products') {
+            $websiteIds = $product->getWebsiteIds();
+            if (count($websiteIds) && !in_array($this->storeManager->getStore()->getWebsiteId(), $websiteIds)) {
+                $websiteIds[] = $this->storeManager->getStore()->getWebsiteId();
+                $product->setWebsiteIds($websiteIds);
+            }
+        }
+
         return $product;
     }