Login flow behaves unexpectedly, requiring login button to be clicked twice.

**Describe the bug**
The login behaviour of Netlify CMS could defy certain user expectations when compared to other systems requiring authentication, and requires the log in button to be clicked twice.

**To Reproduce**
1. Click Login with Netlify Identity on CMS login page

**Expected behavior**
To be successfully authenticated and redirected into the main page of Netlify CMS.

**Actual behaviour**
1. Instead of the login modal dismissing, it tells me I've successfully authenticated (good) and then sits there waiting to be dismissed (not so good).
2. Instead of the successful login redirecting me to the main page of the CMS, I have to manually dismiss the modal window and then - counterintuitively, because I'm apparently now authenticated - click the login button again.

**Screenshots**
Video demo with user details redacted at https://www.dropbox.com/s/0rmuw5eb7crzcxq/Double-login.mp4?dl=0

**Applicable Versions:**
netlify-cms-app 2.15.72
netlify-cms-core 2.55.2
netlify-cms 2.10.192
Github
macOS
Chrome 108.0.5359.94 && Firefox 107.0.1

**Additional context**
I'm onboarding clients into a site built with Netlify CMS. The login flow behaves differently to every other CMS I've used in my career with regard to number of clicks needed. My opinion, maybe - but these things are definite sources of friction and perception-altering moments for client users.