On Bar reports, when "Stack By" is used on a choice column (e.g. Priority) and "Group By" values contain space at the end (e.g. Short Description), then the report does not display those records. Also when used together with 'Display Data Labels' in the Style tab, the bar report does not render and displays the message 'Loading Report..'
After carefully considering the severity and frequency of the issue, and the cost and risk of attempting a fix, it has been decided to not address this issue in any current or near future releases. We do not make this decision lightly, and we apologise for any inconvenience.
The handling of trailing spaces differs between MariaDB and Oracle, fixing the problem for MariaDB would introduce regression for Oracle and the other way around.
The workaround is to cleanup the data, for example to use a fix script to remove trailing spaces in strings that require to be grouped as a single category. If the trailing space is removed, the bar report includes all records.