After creating a new article (or opening an old article without images) and attaching images, you will need to click Save twice to completely remove "dirty" state and be able to publish.
Reproduce:
Create new article without images
Save article
Hard Refresh page (just to simulate that you have opened the article again after initial save). The bug will not necessarily reproduce after "soft" refresh
Add image
Save
ERROR: You will not be able to publish before saving one more time
After creating a new article (or opening an old article without images) and attaching images, you will need to click Save twice to completely remove "dirty" state and be able to publish.
Reproduce: