You are trying to add additional fields in adaptation mode. But field is not shown after applying these changes.
Reproducing the Issue
Go to the Customer work center ( as an example).
Click on Accounts view.
Open any Account.
Navigate to Registered products.
Click on Adapt-> Edit Master Layout.
In EC, you are trying to add additional fields eg: User Status.
Then Click on apply.
If the table / Embedded component is in different Business object other than the BO where add other fields are present, then this will not work.
This feature is considered as future enahancement which will be available in future releases.
PSM fields, Add other fields, Adaptation not working, Adding fields not saved, add PSM fields , KBA , AP-RC-UIF-FLX , Page Layout & Key User Configuration , Product Enhancement