Steps to reproduce:

1. Create a trigger action
2. Add a conditional for NOT Trigger Severity Informational
3. Add trigger action
4. Attempt to remove conditional and click update
5. Trigger action will not remove or function at all

Result:
A trigger action that does not function.
The inability to remove the conditional from that trigger action.
Expected:
A trigger action which sends informational alerts only with no recovery message.
The ability to remove an existing conditional from a trigger action

We wanted a trigger action where informational alerts only sent a single email without a problem/recovery message. This does not work via bug and also exposed other evaluation and update bugs in the Zabbix UI and system.