Since you are using the database in the cloud for branch and your main line you have run into problems. If you create an entity in your branch line that is not in your main line and run your main line again in the cloud it will remove the entity from the database and thus you lose your data. And with the free version that means you have lost your data because you can not retrieve the backup from before running the main line again.
Your branch line should use the local database. Then when everything works as expected you merge the branch back to the main line and deploy again.
Check if you are using the same database by going to the project’s Settings,
In tab ‘Configuration’ doubleclick the configuration name that you are using (marked by the green V)
check if databasename is the same for both branches. They are probably different.