Hello, this question is related to LWC development. I have recently discovered (through many hours of frustration and troubleshooting) that when using an @wire for an apex method that the callback function is not executed if:

• the @wire is triggered by a refreshApex() call
• the serverside data has not changed

In all other scenarios the callback function will execute. 
Is this by design, or is this a bug?  The documentation does not mention anything about the data needing to change for the callback function to execute when using refreshApex(): https://developer.salesforce.com/docs/component-library/documentation/en/48.0/lwc/lwc.apex