Submissions "label" field is lost (empty) after upgrade

We have been using the “label” field of the submissions to identity the complaints.

After updating from version 3.11.44 to the latest version (4.1.16), all the “label” fields submisions are lost and empty.

Luckily it is an upgrade test. What’s going on?. How can we solve it?. Do we have to do an intermediate update?