Hi,

"am I right that DBI still doesn't support this kind of authentication"

I don't think so. I have not used it myself but the DBD::mysql doc indicates that it's supported, see https://metacpan.org/pod/DBD::mysql#mysql_server_pubkey.

(Edit: Did you also update your libmysqlclient? ((I would assume it's required with a major-version upgrade, but worth checking.)) See https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html#upgrade-caching-sha2-password for more info and a workaround.)

Hope this helps!