I sometimes see this when deploying via sqlpackager.exe:

Analyzing deployment plan (Complete) Updating database (Start) Dropping DF_XXX... Creating DF_XXX... Update complete. Updating database (Complete) Successfully published database.

This happens everytime I publish, even though there have not been any changes.

Typically this is caused by Sql taking the create statement from SSDT and changing it, it does things like changes GETDATE to getdate and (0) to ((0)), to be honest I am not 100% sure what it will and won’t change but my fix for this when I get it happening is to go to SSMS and script out the table and copy and paste the constraint back into SSDT, then deploy and it should stop.