I have same issue with resolved, take inventory_source_item table backup first.
Run sql query:
INSERT IGNORE INTO `inventory_source_item` (source_code, sku, quantity, status)
select 'default', sku, qty, stock_status from (`cataloginventory_stock_status` as `lg` join `catalog_product_entity` as `prd` on((`lg`.`product_id` = `prd`.`entity_id`)))
Apply command:
php bin/magento indexer:reindex
php bin/magento cache:flush
