Up until recently, you were able to rename a layer then hit tab to rename the layer below it. This still works some times, but when you have a group of collapsed frames with child layers, hitting tab starts navigating around the window like keyboard-navigating around a website.
Feels like a bug or some weird condition is making tab some times work and some times not…

Edit: oh my god it depends on where your cursor is… please change this. Tab should move around the layers list while renaming until someone hits escape or enter to cancel or commit the current renaming. While the field is visible and active, tab should be reliable regardless of the cursor’s position.

After more messing around, it still breaks out into navigation some times even with the cursor over the layers list. Sad.