The installation in vmware only takes only about 5 min.   Did a new test, installed it, skip updates, redmin works (so mariadb works in the background for webmin). In webmin at mariadb same error with option: "access denied for user "adminer@localhost" and gave a user and password login option. (note, that this time i did not change the password.) Then login to ssh/terminal, and do a reboot.  (For my case i will be running it on a machine, only during programming hours and will be shutdown afterwards)   After the reboot, redmin, don't work. And in webmin the service of mariadb can't be accessed anymore.  Error!  MariaDB is not running on your system - database list could not be retrieved. After reboot these errors:

Command used:  journalctl -xeu mariadb.service
[...]
InnoDB: Starting shutdown...
[ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
[...]
[ERROR] Unknown/unsupported storage engine: InnoDB
[ERROR] Aborting

  For time being, i wanted a fast deployment instead of installing debian + all software manual. Time going almost to the point that doing it manual might be more fruitfull. However then i still have to learn how to access mariadb in case something like this happens there. So i figure we can better try to fix this and learn from it. Only after i have my files/mariadb backu export and import scripts/manuals ready then i will go work fully with system. Dont want my notes, history etc to be lost in files i can't access. Can you follow my steps and do the reboot after install and then see for yourself?