TSQL Re-Enabling Contraints take a long time
As expected.

For example, CHECK constraints: every row must be checked for every check constraint.

If you have 3 CHECK constraints and 370 million rows, that's 1.11 billion checks to be done in a single ALTER.

Each UNIQUE constraint must check all 370 million rows, in the same ALTER.

This is why I don't normally disable constraints in my DWs.
It takes too much time. Especially when you get to billions of rows.