Hello @thrivewithfiona,
Thanks for updating the thread.
I loaded the bunch of pages in Cornerstone and I am not facing any issues while loading and editing the contents in Cornerstone.
Please inspect the Section or element and under Customize > Setup > Hide During Breakpoints you can see the buttons. On my end this is also working fine.
I have recorded a screencast, please take a look. Link shared in secure note.
A page designed using Cornerstone can’t be edited using other page builders like Gutenberg. Same logic applies other way around too, page designed using Gutenberg can’t be edited using Cornerstone.
We are still unable to replicate the problem you are facing. Having said as you are facing issues with Cornerstone, can you please let us know browser version that you are using?
Thanks.