This is seemingly a long-standing bug with the patrolled/unpatrolled revisions that occurs when a user with autopatrol user right (i.e., autopatrolled users and administrators) loses that status. Their previously automatically patrolled, and possibly their manually patrolled revisions prior to them gaining that status (sorry, can't remember exactly on this point), become unpatrolled.
MediaWiki version: 1.34.2
System Information:
Vivaldi 3.1.1929.45 (Stable channel) (64-bit)
Revision 1eb3263017ed42270818939fbff241845938a81f
OS Windows 10 OS Version 1909 (Build 18363.959)
JavaScript V8 8.3.110.13
Flash 32.0.0.387 C:\WINDOWS\system32\Macromed\Flash\pepflashplayer64_32_0_0_387.dll
User Agent Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.119 Safari/537.36
Command Line "C:\Users\Wylie\AppData\Local\Vivaldi\Application\vivaldi.exe" --flag-switches-begin --flag-switches-end --enable-audio-service-sandbox --ppapi-flash-path="C:\WINDOWS\system32\Macromed\Flash\pepflashplayer64_32_0_0_387.dll" --save-page-as-mhtml
Executable Path C:\Users\Wylie\AppData\Local\Vivaldi\Application\vivaldi.exe
Profile Path C:\Users\Wylie\AppData\Local\Vivaldi\User Data\Default
original Written by @dmehus