Portfolio MS Teams Notification are not being sent

### Current Behavior

Hi,

our teams notification are not beind sent from out Dependencytrack.

We use following Configuration:

System-Notifications with the same Web-Hook URL are being sent and received.

Do we overlook things?

### Steps to Reproduce

1. Configure the Teams Notification as in the screen shot above

2. If projects get new vulnerabilities no notification is sent

### Expected Behavior

The notification should have been sent

### Dependency-Track Version

4.7.1

### Dependency-Track Distribution

Container Image

### Database Server

Microsoft SQL Server

### Database Server Version

SQL 2017

### Browser

Google Chrome

### Checklist

- [X] I have read and understand the [contributing guidelines](https://github.com/DependencyTrack/dependency-track/blob/master/CONTRIBUTING.md#filing-issues)
- [X] I have checked the [existing issues](https://github.com/DependencyTrack/dependency-track/issues) for whether this defect was already reported