This post just went live and you can see that the setting did not stick.
I checked the box to disable post image / page header and checked it on preview – looked good. I then scheduled the post and previewed again – looked good.
During this test all Plugins were disabled except the essential ones:
– GP Premium
– Jetpack by WordPress
– Leadpages connector
Everything else was deactivated.
Any thoughts on what I should try next?
Thanks for your help!