More detailed description of conditions is given here.
Limit - 2000 conditions.
1. Choose in the "When" block a temporary condition, which is met only once. For example: when the client wrote a message or the date of creation of the ticket - time has passed - 12 hours. Exception - the "Always" condition;
2. All new incoming tickets get the status "New." At any action with a ticket, the status changes to "Opened" and cannot be returned to the "New" status. If the trigger should work for incoming new tickets, select the condition "Status - new" in the "What" block, and at any change in the ticket, the trigger will not work the second time;
3. Add a cancellation of the condition or an action that will start the trigger again. For example, the trigger reacts to tickets with the "Failure" tag - condition and sends a message to the client that the "Failure is eliminated" - action. If the trigger works under the specified parameters, then after sending a message, the system checks the tickets again and finds the tickets with the "Failure" tag, thus restarting the trigger for processing and sending the message and doing so many times. Bottom line: add one more action - delete the "Failure" tag.
After making changes, click "Save," and the trigger will work in automatic mode.