https://www.phpmyadmin.net/news/2019/11 ... -released/
In summary, if PHP 7.4 is not supported on phpBB 3.3 in combination with phpMyAdmin (any version) being used, then people will not be able to also use MySQl 8.0.x, which offers better performance and security than MySQL 5.7.x and below, unlessDue to changes in the MySQL authentication method, PHP versions prior to 7.4 are unable to authenticate to a MySQL 8.0 or newer server (our tests show the problem actually began with MySQL 8.0.11). This relates to a PHP bug https://bugs.php.net/bug.php?id=76243. There is a workaround, that is to set your user account to use the current-style password hash method, mysql_native_password. This unfortunate lack of coordination has caused the incompatibility to affect all PHP applications, not just phpMyAdmin. For more details, you can see our bug tracker item at https://github.com/phpmyadmin/phpmyadmin/issues/14220.
By chance, is this the planned implementation of PHP 7.4 for phpBB 3.3 and 4.0, Marc? If so, please lock and disregard this suggestion.