Self Signed SSL login works for 6.9.1, does not work for 7.0, 7.x

I was on autoupdate on google-play-app-store
Downgraded to 6.9.1
tried a few things.
I'm going to not upgrade beyond 6.9.1 for a while.

Expected behavior

• start app
• fill in username, passwd, self-hosted ssl url
• dialog prompts to ask to allow self signed unverifyable ssl certificate, say yes,
• should login, for 6.9.1 site screen shows up, but does not for 7.0 and above

Actual behavior

• does not login after wordpress android app 7.0 vercode:376 upto 7.9.1-rc2
• login succeeds for 6.9.1 vercode:360 (apk retrieved from apkmirror)

Steps to reproduce the behavior

1. made fresh self signed CA certificate and server certificate
   create a cacert.pem, priv.key, host.crt, host.key as described in
   http://www.eclectica.ca/howto/ssl-cert-howto.php
2. desktop: add certificate to firefox on desktop browser
3. desktop: check that wordpress working from desktop browser
4. android: add cacert.pem into android settings->general->security->certificates->user
5. android: check that wordpress site working from android browser
6. install and try each wordpress apk

App logs uploaded for both cases
wp70_log.txt
wp691_log.txt

Repeated a few times to be sure
7.0, vercode:376 was released on Apr-4-2017: API:16-25
6.9.1, vercode:360 was released on Mar-28-2017: API:16-25
I had not noticed this sooner as had not used wordpress app on phone for a while

Tested on [device], Android [version]

LG G3 D855
Android 6.0 lollypop V30b-GLOBAL-COM

Start by comparing the attached wp70_log.txt and wp691_log.txt, then reproduce the login flow across the reported app versions on Android with the self-signed certificate setup. Done means a self-signed HTTPS WordPress site can log in successfully on the affected 7.x versions, as it does in 6.9.1.