thanks for your answer!
Iam using the on-premises data gateway with scheduled refresh with MariaDB as data source, so on the MariaDB-side i can only see the queries fetching all data for syncing them into "something" PowerBI can access (i dont know anything about PowerBI internals), but i dont see the specific queries of the reports since they are not done on the original MariaDB source db.
I have not created that existing reports .. but maybe i can switch them somehow to use MariaDB directly via the on-premises data gateway to see the queries on MariaDB? i have not figured out yet how to change that reports to DirectQuery. The most promising place to change that is in the screenshot below (some private details removed, the data sync is working correctly for that datasource. that tooltip "Manage Connections and Gateways" does not allow change to DirectQuery):
thanks in advance,