Magento 2: Admin Customer Listing Not Displaying Record

I will NOT recommend to mess with Magento database directly.

Try this:

php bin/magento indexer:reset customer_grid
php bin/magento indexer:reindex customer_grid

Reset your databse: Magento 2: Not showing customers in backend grid

update indexer_state set status = 'invalid' where status != 'valid';

[EDIT]:

We should use

php bin/magento indexer:reset customer_grid

Possible errors:

--Disable safe mode

update magento.indexer_state set status = 'invalid' where status != 'valid' Error Code: 1175. You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column To disable safe mode, toggle the option in Preferences -> SQL Editor and reconnect. 0.000 sec

Reference here: https://stackoverflow.com/questions/11448068/mysql-error-code-1175-during-update-in-mysql-workbench

--Not able to run php bin/magento indexer:reindex customer_grid

Customer Grid index is locked by another reindex process. Skipping.

show processlist; 
kill "id number";

Or, we can restart mysql server.

--A large number of database - php -dmemory_limit=512M

If you have a large number of database, run the command with

php -dmemory_limit=512M bin/magento indexer:reindex customer_grid

Or should increase the memory_limit ~ 512M in php.ini