Thank you for reaching out to us!
I am not sure I completely understood your issue, so please bear with me - I will do my best to help.
I have tried to replicate it, but could not. From my understanding this seems to be happening when you are using the ‘Edit’ blue button on that page.
Have you tried adding the widgets by going to Appearance > Customize > Widgets > Page: name of your page > and adding them here. Note: make sure to be on that page when you access the customizer.
Thank you Mihaela for your reply.
Going into widgets doesn’t work either. The problem is that I cannot use this widget - the image doesn’t show, the title, the buttons do not appear. You can see on the below screenshot that although I have set a widget, the page area is still empty.