I have lost the ability to adjust the sequential history of features in my sheetmetal parts. Is there a setting that I inadvertently changed?

Check the lower-right of the screen for Structured vs. Innovative mode, you'll want Innovative.

I checked and my scene is set to innovation mode. I have attached a sample part showing the issue. The flange on the right was the original design intent, then I added a few more bends to the part but left the original return flange. In the past I was able to take the original flange which occurred earlier in the tree and drag in down to the bottom of the tree as if it was the last feature created. This is a simple example but in larger assemblies it has become necessary to recreate a significant number of features. What else could it be?

We are investigating this.