Known Issue Workaround: Email Alert Misbehaves with Queues
This is in regard to this known issue.
This bug is in very old Email Alert code and Salesforce is not prioritizing work in that part of the code base. Here’s a fairly straightforward workaround that replaces the Email Alert with a Send Email action in a flow.
For this workaround, we’ll use the exact starting conditions found in the Known Issue. However you can apply this to other scenarios where Email Alert is showing this unwanted behavior.
Let’s assume that you want your Approval Process to Set the Owner of a Case to a Queue. You want email to go out to the Queue Email but not the full set of Queue members. Email Alert is broken here. It sends too many emails out. So, instead of adding an Email Alert to your Approval Process, Create this Record-Triggered Flow:

Note the checkbox outlined in red. In order to call actions like Send Email on a Record-Triggered Flow, you need to use the ‘Asynchronous’ path.
Next, place a Send Email Action on that path:

However, we’re not quite done. We need to do a Get Records on the Queue to extract the Queue Email:

Here’s the final flow:

Now we can set the recipient of the Send Email action to be the Queue Email field from the Queue:

In the above example, I just threw some placeholder text into Body and Subject, but you can create a Text Template in Flow and add merge fields to add useful information into the Email. You can also add a URL that takes the user back to the case.