When we import product through any plugin or magento migration tool it migrates url rewrite table as well and on url rewrite when we may have any url path ” (Blank) in few entries
We just need to clear those entries from database
DELETE FROM `url_rewrite` WHERE request_path='';
And arrange setup:upgrade and clean cache after that homepage will work
php bin/magento indexer:reindex php bin/magento setup:upgrade php bin/magento cache:clean php bin/magento cache:flush
