Hi! This does appear to have fixed it. I copied the plugin to the production server, just to be sure, and it seems to work there, too. But as we noted, the issue is intermittent, so I’ll keep an eye on it.
Now that I think about it, the problem occurred after an upgrade of the Subscriptions plugin, not yours. Is there any feedback I should give them about this conflict?
Thank you for addressing this so quickly!