(potential) work-around for Playstore authentication issue

[NexusDude]

This continues to be an issue for my Pine64.

For my Pine64, it occurs consistently, sort of.

• Affects all Android images -- rooted, so-called "un-rooted", RemixOS
  
• GP Store will always work, initially, upon booting for the first time
  
• GP Store will eventually stop permitting app downloads and app rating submissions. Even if it's working now,  give it time...
  
• Once it fails, it continues to fail, until you apply a work-around fix, or re-image.
  
• Once a workaround fix stops working, it continues to fail. You must try a different fix, or re-image.
  

(The DD images of Android all test as rooted.)

What varies:

• The length of time that GP Store works. When you boot for the first time, or succesfully apply a workaround fix, it will work... but eventually it stops. You may get downloads & rating submissions working for hours, or only seconds. Typically, you can get in a few installs, while it's working, before it quits again. You many only get 1 install in, though, or none at all. In a one hour session of Android, you may apply fixes several times, without rebooting.
  
• Sometimes, workaround fixes stop working. 
  
• Pop-up vs. Notification. How the app informs the user of failure varies. A pop-up error message likely mentions DF-DLA-15. An Android notification always mentions authentication failure.
  
• Multiple notifications vs. 1 notification maximum -- sometimes, you must clear the notification to be informed of future errors; other times, you can get multiple notifications
  
• Various fixes, sorted by speed:
  

1. Settings / Accounts / Add New Account / Google
   
2. Settings / Accounts / Add New Account / Google / enter gmail of existing Google account
   
3. Settings / Accounts / select account / Remove Account / Add New Account / Google / enter gmail of account you just removed
   
4. Clearing GP Store and GP services caches, rebooting
   
5. Wiping the Dalvik partition, rebooting
   
6. Reimaging your microSD card, booting
   

Other things I've tried, that never helped or seem unrelated to this issue:

• Gmail accounts with 2-step verification, vs. those without
  
• Using only a single Gmail account, vs. using multiple Gmail accounts
  
• Using Gmail accounts with Play Store credit, vs. those without a payment method
  
• Rebooting
  
• Using other images of Android
  
• Using a time app to document time clock differences
  
• Turning account syncing off/on
  
• Various power adapters
  

What I have not yet tried:

• Heat sinks / fans / cooling my house more
  
• RTC battery
  
• Shorter Cat6
  

What I've had trouble trying:

• Wi-fi dongle
  
• Mock Location -- there doesn't seem to be a way to set this
  
• Using a time app to reset the time from NTP
  

Few have voiced their frustration on pine64.pro, which seems odd, considering the various threads on this issue. Maybe they didn't want to bother registering a new ID there?