K4 This device is not authorised as a test kindle

[Darthagnon]

I have a few old Kindles, one of which is my main: a Kindle 4. I like the buttons and have even replaced the motherboard.

It is not registered to any Amazon account, as I use KOReader and have multiple Kindles (other's registered to Amazon).

Usually in aeroplane mode, one day I connected it to Wifi. After a few minutes, I got "This device is not authorised as a test Kindle by the developer of this item. Please contact the developer." And then my jailbreak was disabled. I did not attempt registering the Kindle (nor do I plan to, it's old), which some have suggested may cause this error.

It's on the latest firmware for K4, jailbroken and I've used RenameOTAbin and ShutTheBackDoor (BinaryRenamer I tested as non-functional on this K4). So it's not getting any OTA updates. What gives? How can I prevent it losing its jailbreak when connected to WiFi?

There's a couple other people over the years who have had the same issue as me:

• https://www.mobileread.com/forums/sh...d.php?t=270856
  https://www.mobileread.com/forums/sh...d.php?t=352957

I used the same solution they did and reinstalled the jailbreak, but this is quite annoying, as it means I can't wirelessly transfer books. Is it because the K4 jailbreak uses revoked dev certs or something? Is there anything I can do to prevent this from happening?