Can't re-enter my GMail password! Settings > Mail > Gmail: tap the "Re-enter Password" and the window starts to load but then disappears.

In my Settings > Mail, Contacts, Calendar, Notes under accounts is my GMail account which has been working perfectly fine on my iPhone 6S until I changed my GMail password. Naturally, the next time I go to check my GMail email on my phone (NOTE: I do not use a separate GMail app) it tells me to update my password in Settings.

When I attempt to do this, by tapping on the blue "Reset Password" text, the Gmail window starts to open but then immediately disappears!

I've been scouring the internet all day in search of a solution. I've tried powering down the phone (properly) and restarting it. That didn't help. I've tried Settings > Mail, Contacts, Calendar, Notes "Add Account" but when I tap "Google" I get the same thing - the window starts loading, then it disappears.

Just out of curiosity, I also tapped the others (iCloud, Exchange, Yahoo, AOL and Outlook) on the list and they all open a screen except for Google and Yahoo, which also starts loading but then immediately disappears. I wonder why this happens for only Google and Yahoo? (I do not have a Yahoo email account configured on this phone. Only Gmail and Exchange (for work, which is functioning perfectly, no issues with that one)

So, when the Google signin/setup window failed to load, I tried tapping on "Other" on this list, thinking maybe I will manually add my GMail account again (as IMAP), but the iPhone will not let me do that without also configuring incoming/outgoing mail servers as if it's a POP setup? I gave up on that idea.

What I really want is to simply reset my password on my phone for my Gmail account in Settings. Has anyone else had this issue? Is there a known bug regarding this? Is there a workaround solution to this? Am I doing something wrong? Do I need to take this phone to an Apple store and get help there?