When deploying Queues with Gearset the members section is automatically included and the member list is deployed to the target org. Gearset has a suggested fix to sync the queue members with the target environment but it doesn't always work.

Salesforce supports deploying queues with an empty list of users as queue members are more like data than metadata I suggest a feature toggle in Gearset where the users section of the queue is ignored for deployments to preserve the user list in the destination org.
Our company and many others probably maintain the queue users directly in production as it's done with public group membership.

Here is an excerpt of the xml and what to remove to preserve the queue members in the target org.

<?xml version="1.0" encoding="UTF-8"?>
<Queue xmlns="http://soap.sforce.com/2006/04/metadata">
<doesSendEmailToMembers>false</doesSendEmailToMembers>
<name>QueueNameTest</name>
<!-- Remove from here
<queueMembers>
<users>
<user>bla@blabla.com</user>
</users>
</queueMembers>
Remove to here-->
<queueRoutingConfig>Test</queueRoutingConfig>
<queueSobject>
<sobjectType>Case</sobjectType>
</queueSobject>
<queueSobject>
<sobjectType>LiveChatTranscript</sobjectType>
</queueSobject>
</Queue>