Version 10.15 UM Trigger - Null and blank field in filter condition being treated differently in webMethods 10.15

I have a scenario where in webMethods 10.3 Universal Messaging trigger, a filter condition is put on a field to check for blank. This condition is working fine in 10.3 where that field has no data or the field is absent/null.
While upgrade, i found out that same condition is failing for field absent/null scenario in 10.15.
I have listed down the scenarios below -
if Field 1 =null is published over UM :

10.3 IS and 10.3 UM trigger filter condition
Field 1=‘’ → data is subscribed

10.3 IS and 10.15 UM trigger filter condition
Field 1=‘’ → data is subscribed

10.15 IS and 10.15 UM trigger filter condition
Field 1=‘’ → data is not subscribed

Please let me know if there is some setting that needs to be done to make this condition work in version 10.15 same as in version 10.3.
Any help is appreciated.

If there is a difference in behavior and if you installed the latest fixes available already, I recommend creating a support ticket and asking about it directly to SAG. If you haven’t installed the latest fixes available, try installing them first.