Recorded automation gets ... stuck?

So I’ve had this problem on and off, going back to previous version of Cubase, and again in 12. Sometimes after writing some automation, the automation kinda gets stuck. Write Automation is turned off, Read is on. But the track won’t follow what I’ve just automated. It’s also not possible to edit the automation track at all, and the track stays red, even though write is not activated (track or global). Here’s a basic example of what I mean, in this case when automating the bypass of a plugin. I should note the bypass automated is not being followed when playing back:

Like I said, this happens randomly pretty much. But it can be very frustrating. if I close the project and re-open, it resets itself, and the automation is there and editable. Or maybe I’m just being an idiot and doing something wrong?
I’m using a CC 121 controller - I’m wondering if it has anything to do with that. I’ve had some other oddities with that.