ZC v1.5.8a
php 7.4
phpMyAdmin v4.9.7
MariaDB v5.5.68 / v10.3.29


After upgrading ZC from 1.3.9h to v1.5.8a, everything works fine, and the next thing to do is switch from MariaDB v5 to v10.

I use phpMyAdmin to export the database from MariaDB v5, and import to v10. No error message here, and DB name, username, password are all the same.
Stop v5 and run v10. The website says "There seems to be a problem connecting to our database." Error log shows:

Request URI: /index.php?main_page=product_reviews_info&products_id=2&reviews_id=10&zenid=1k4o0 1rd1saah9js23cvlhnj30, IP address: 124.243.150.207, Language id
#1 mysqli_connect() called at [/web/includes/classes/db/mysql/query_factory.php:76]
#2 queryFactory->connect() called at [/web/includes/init_includes/init_database.php:22]
#3 require(/web/includes/init_includes/init_database.php) called at [/volume1/web/kendo158/includes/application_top.php:199]
#4 require(/web/includes/application_top.php) called at [/volume1/web/kendo158/index.php:25]
--> PHP Warning: mysqli_connect(): (HY000/2002): No such file or directory in /web/includes/classes/db/mysql/query_factory.php on line 76.
Stop v10 and run v5, and everything is back to normal. It looks like phpMyAdmin can see MariaDB v10 on my server, but ZC can't. Do I miss any step?