Host 'localhost' is not allowed to connect to this MariaDB s

[trejder]

I have just installed a fresh installation of 8.2.x branch. The computer had some old XAMPP installed before, but everything was purged.

Any attempt to use database (i.e. trying to run phpMyAdmin from the main localhost page) ends with:

> Host 'localhost' is not allowed to connect to this MariaDB server

Adminer has the same error and so the HeidiSQL.

I am completely puzzled on what should I do next? Any help is highly appreciated.

[trejder]

Fresh-install of 8.2.4 doesn't have this problem, so this seems either temporal or obsolete.