We can resolve exception on category page “Bucket does not exist” by one of the below solution:
1) One of reason because of Page Cache, Static resource or Indexer not updated. So try remove /var/ and /pub/static/ (don’t remove .htaccess) execute below command.
php bin/magento cache:flush
php bin/magento setup:static-content:deploy -f
php bin/magento indexer:reindex
php bin/magento setup:di:compile (optional)
2) Problem with layered navigation, when we try to change or select sub category when base/parent category is set as anchor. Probably solution we can set value of “No” of base/parent category and once again change it to “No”. It should resolve our problem and sub category page will work from layer navigation.