Behavior Tree task bug? Blackboard Key Selector variable default "None" value being overridden in editor

Hi all, I’m experiencing what appears to be a bug with BT tasks in 5.3.2 and am looking for confirmation and/or potential workarounds.

For me the behavior happens with any task that has an instance-editable variable of type Blackboard Key Selector. Default value of the variable is set as “None” in the details tab of the task blueprint, however when the task is implemented in a behavior tree the editor continually overrides the variable from “None” to the first entry in my blackboard key list. Clicking the little arrow next to the field resets it to the default None value, but as soon as I save the editor once again changes the value back to the first BB key entry.

I created a simple test task to confirm the behavior isn’t being caused by a problem in my existing tasks - just a bare-bones task blueprint to sanity check the apparent bug. Here are some screengrabs:

Am I missing something? Is anyone else experiencing this issue? And if yes, is this a feature or a bug? It’s problematic having the editor making key selections for me in situations where I want a particular instance of a task to retain a default value of “None” for a BB key selector variable.

Thanks in advance!