Wrong version of Xquartz reported by brew

My iMac reports the following, which seems confused.

 $ brew info xquartz

xquartz: 2.8.1 (auto_updates)

https://www.xquartz.org/

/usr/local/Caskroom/xquartz/2.8.1 (103.5MB)

From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/xquartz.rb

==> Name

XQuartz

==> Description

Open-source version of the X.Org X Window System

==> Artifacts

XQuartz.pkg (Pkg)

==> Analytics

install: 11,088 (30 days), 30,375 (90 days), 130,537 (365 days)

$ brew config    

HOMEBREW_VERSION: 3.2.13

ORIGIN: https://github.com/Homebrew/brew

HEAD: 109f24fd601177dea4a754b43efe684903db2a83

Last commit: 3 days ago

Core tap ORIGIN: https://github.com/Homebrew/homebrew-core

Core tap HEAD: 3bb285a5031102575de4defe0185e42d21199a1d

Core tap last commit: 2 days ago

Core tap branch: master

HOMEBREW_PREFIX: /usr/local

HOMEBREW_CASK_OPTS: []

HOMEBREW_DISPLAY: /private/tmp/com.apple.launchd.OViC2jtB96/org.xquartz:0

HOMEBREW_MAKE_JOBS: 4

Homebrew Ruby: 2.6.3 => /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby

CPU: quad-core 64-bit kabylake

Clang: 13.0.0 build 1300

Git: 2.30.1 => /Applications/Xcode.app/Contents/Developer/usr/bin/git

Curl: 7.64.1 => /usr/bin/curl

macOS: 11.6-x86_64

CLT: 13.0.0.0.1.1630607135

Xcode: 13.0

XQuartz: 2.7.7 => /opt/X11

$ brew doctor    

Please note that these warnings are just used to help the Homebrew maintainers

with debugging if you file an issue. If everything you use Homebrew for is

working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: Your XQuartz (2.7.7) is outdated.

Please install XQuartz 2.7.11 (or delete the current version).

XQuartz can be updated using Homebrew Cask by running:

 brew reinstall xquartz

When I am running Xquartz it correctly reports that it is running version 2.8.1 and is up-to-date. But the above shows that brew is still confused even though brew itself has the 2.8.1 version showing as installed.