Adding logo does not update the Appearance page

[bregman90]

The page is this one: https://muskegonvotes.wpengine.com/wp-admin/admin.php?page=elections. In the Appearance tab.

Repro: In the logo section, tap Select Image -> Upload Image -> Choose Image.
Expectation: Logo should appear on the page after choosing image.
Behavior: Logo is missing, but it appears after Save Changes.

[paulschreiber]

1. Can you reproduce this elsewhere? I can't reproduce it on elections.usdr.dev or locally.
2. Did you observe any errors or warnings in console?
3. Please provide credentials to access to the site (not here).

[bregman90]

1. I tried on my WordPress.com site and also wasn't able to reproduce it.
2. Yes, hm, maybe this?

Uncaught TypeError: Cannot read property 'url' of undefined
    at h.Collection.<anonymous> (admin.min.js?ver=0.8.12:1)
    at p (backbone.min.js?ver=1.4.0:2)
    at f (backbone.min.js?ver=1.4.0:2)
    at l (backbone.min.js?ver=1.4.0:2)
    at h.Collection.n.trigger (backbone.min.js?ver=1.4.0:2)
    at h.Collection._onModelEvent (backbone.min.js?ver=1.4.0:2)
    at p (backbone.min.js?ver=1.4.0:2)
    at f (backbone.min.js?ver=1.4.0:2)
    at l (backbone.min.js?ver=1.4.0:2)
    at i.n.trigger (backbone.min.js?ver=1.4.0:2)

3. Added you.

[paulschreiber]

WP Engine's password reset page is also generating many JS errors (and failing to process resets):

I've reached out to WP Engine support to try and get logged in.