It's time for another round of software updates for all 10th and 11th generation Kindles, including the Kindle Paperwhite 4 and 5, along with the Kindle Oasis 3, the current and previous entry-level Kindle, and the Kindle Scribe. The new software version is 5.16.6, and it's available to download from the Kindle Software Updates page
So every single book I transferred from Calibre was deleted : r/kindle
How To Force Software Update On Your Kindle Paperwhite 11th Gen
Jailbreak Firmware 5.16.2? : r/kindle
Kindle firmware 5.16.4 available now : r/kindle
Kindle Scribe User Group
LanguageBreak can jailbreak Kindles running software versions 5.16.2.1.1 or lower - Liliputing
So every single book I transferred from Calibre was deleted : r/kindle
New Kindle Software Update 5.13.1 Released
is updating Kindles to make them easier to navigate
Releases First Software Update for the Kindle Scribe (5.16.1.2) – eWritable
Kindle firmware 5.16.4 available now : r/kindle
Some Older Kindles Require Update by October 1st