Grafana does not hide NULL values if they come from a CASE WHEN

Hello everyone, I’m trying to create a panel in Grafana 10, using MySql as a database.
The bars should represent:

  • Available hours
  • Utilized hours

The available hours will always be more than the utilized ones, but sometimes it could be vice versa. So, I’d like to set up a system where if the utilized hours exceed the available hours, then the bar for utilized hours turns yellow using overrides. So, I thought of using a CASE WHEN where I state:

  • Available hours
  • Utilized hours1
  • Utilized hours2

Thanks to MySql and the CASE WHEN, I instruct that if Utilized hours1 is more than Available hours, then it should display NULL, and we do the opposite for Utilized hours2. The problem is that Grafana doesn’t hide NULL values if they come from a CASE WHEN clause, what can I do?