I'm trying to make a simple change to Case Management record page (add tab)
I go to Lightning App Builder make the change, press save and it shows saved. When I go back to Lightning App Builder main page in setup I see that Last Modified changes
I go back to the page and the changes are not there.
I tried to create a new page instead and got more or less the same result. The header is saved ok the rest is not saved
Any idea what could be the problem?