Weird navbar back button transition if title not changed

Have noticed a weird behaviour in my apps lately caused by me not changing the ‘Title’ on the Navbar between Master / Detail screens.
It looks terribly hybrid/css slow if you don’t change the Title.

See this codepen to demo the problem.
Codepen

Swap lines 55 and 56 (ie. on the detail html change or don’t change the Title text) and watch the navbar when you return from the detail view back to the list view.

Assume it is due to the animation being triggered.

For now all I do is append a space to my Title on a detail view.

Not sure whether to file a bug

Cheers
Darren