[DarrenHill]

Normally phpMyAdmin is just for setting up/inspecting/editing/removing databases. Once things are up and running, you just need the MariaDB server.

[Klojum]

I deleted all unnecessary users, I left only kodi% and root but no change.

Did you do 'flush privileges' as well ? Or a database restart?
Just asking.

[black_eagle]

Can you log into your NAS with SSH ?  If so, can you log into mariadb with mysql -u kodi -p and then inputting the password when it asks for it ?

[zeze31]

I'm not sure how, but it works.
Without going through mariaDB.
kodi created a new base in v5 I don't know where on the NAS, I import my old base and it works again via port 3306.
I must have mysql on my NAS, one in 3308 and another in 3306

[Klojum]

Port 3306 is the default for MySQL servers. So either you changed it manually to 3308, or some other installation did that automagically.