BUG: Custom property's change script not triggering and enabled set to null

Ignition platform 8.1.48

The Setup
I have a session.custom.mySessionScopedVariable variable with no bindings. On a main navigation view, there is a selection dropdown that is bi-directionally bound to this variable. When the dropdown changes, session.custom.mySessionScopedVariable changes. I have configured a change script on session.custom.mySessionScopedVariable to make session scoped changes on this main dropdown selection. I've also created view scoped custom variables bound to session.custom.mySessionScopedVariable with their own change scripts to make view scoped changes on dropdown selection.

The Issue
The session scoped change script never runs, but the bound view scoped change scripts do. When I actually open up props.json and look at the configuration for the session scoped variable, the onChange key shows the script, however, enabled is set to null. I can uncheck the enabled checkbox in designer and the props.json enabled changes to false. When I check the checkbox and save, it goes back to null. I can manually change the props.json to enabled: true and the script still does not run. Then, on the very next save from designer, it goes back to null. What is going on? I've deleted the script and recreated it and it's the same issue.

Any help would be greatly appreciated.

Huh. Sounds like a bug. And easily reproduced. You should open a support ticket. (That's how bugs get fixed.)