Problem trigger with OLD. or NEW. values usage

Have trigger functionality for data "change log" collecting in separate table.
Trigger compares OLD. with NEW. and changes are inserted into H table.

This works correctly with MySQL (5.6, 8.0 atleast).

In MariaDB this does not work.

Script provided shoud produce 4+5+4 rows in H table, and should not end up with error
Unknown column 'I4' in 'field list'

Now works only middle part of trigger - with removed WHERE clause.