@hube2 That didn’t work sadly but THANK YOU nevertheless, because it gave me the idea to run the filter on a different action: I’ve moved it from admin_menu to admin_init and it’s all working now, both columns 🙂
I suppose I was being dense, in that I was displaying the field on a custom post page, so it wasn’t an admin menu as such… But then I’d have thought that neither column would have worked if that was the actual problem!…
Anyways, thanks again 🙂
