Affected are all versions running on MariaDB 10.3. having a Column as TEXT datatype

The error that occurs is:

Error Code: 1815. Internal error: IDB-2015: Sorting length exceeded. Session variable max_length_for_sort_data needs to be set higher.

The problem appears as soon as the "Rückmeldung-Inhalt" field is dragged to the report or trying to filter on this field.

The variable max_length_for_sort_data was checked by:
by

show global variables like '%max_length%'; 

and WAS 102400, then set to something > 8.000.000 (the actual allowed maximum), but this didn't help.

The problem is the ORDER BY. Leaving it out works. (This time, the HAVING and GROUP BY are not the problem.)

It was verified also on ILS Nürnberg and our internal test servers that the version 10.3. is the problem; with 10.5. it works.
Problem is with 10.3 works with MariaDB Version 10.5.

However, we changed to TEXT because MariaDB 10.5. has the problem of:
Internal error: CAL0009: (3)Create table failed due to char, varchar and varbinary length may not exceed 8000.