When the fields get empty during editing API Connector, they disappear.

When the fields get empty during editing API Connector, they dissapear. After save editing, they are not longer available in UI.

It happens on upstream (1.11.0-20201104) or build#5 . This didn't happen on build#4 so it is a regression.
Our test didn't catch this issue during the last build5 test cycle due to issue ENTESB-15132 .