Cronjob runs error due to outdated Mariadb?

I have set correctly the cronjob adn auto archiving, but I get the errors in the diagnostics and also the Load Data Infile warnings.
Are we sure that Matomo is compatible with version 10.3.35-MariaDB ?

Yes, Matomo does support MariaDB 10.3 (https://matomo.org/faq/on-premise/matomo-requirements/).

Can you check the output of the cronjob (where you redirect it to with > /path/to/file)?

where exactly I should chek it? I have a run log, is that what you mean?