Problem with "Texting"

I´m trying to make a Alarm-Pager for my Red Cross medical unit. The alarm sender works without any Problem, but the "Pager" doesn´t work.

The Pager-Screen should only react on presetted Words. When these words are detected in a Message, the app should play a Sound and set the Label-Color to "red" until the confirmation-button has been clicked.

I tested it with the AI Companion and with the .APK but whatever I´m trying, it doesn´t work at all.

The Attachment shows my Blocks-editor. Can you tell me, where the mistake is?