First I tried, my solution is not the solution, and I forget to tell that there also was another debug warning
Code:
mysqli_real_escape_string() expects parameter 2 to be string, array given in /home4/hubertbe/public_html/tst154/includes/classes/db/mysql/query_factory.php on line 115
Which is, technically speaking a warning, but I don't get any reward points shown nor calculated in my invoice totals.

What is strange it's these warning are about my custom module and not reward points. I don't get any message coming from reward points files.

I'm missing something here...