Have the required changes in my.cnf been made?
Installing and upgrading help
Issues Upgrading to Moodle 3.4
php mysql_compressed_rows.php -i
That will show the global setup of the databases on the db server ... which, in your hosting, is probably a dedicated DB server NOT on the same server as your code (but I could be wrong).
Also ask them to run the same command with a different switch:
php mysql_compressed_rows.php -s
The -s should show the SQL needed to get your DB in compliance.
The reason this is happening I suspect is that the environment check looks at the global setup for the entire DB server as opposed to the setup of the specific database your Moodle is setup to use.
'spirit of sharing', Ken