shell markup fails after certain parameter expansion expression

echo ${1%{*}

Markup after the command keeps the same unless there is an extra '}' somewhere after it (which is syntax error).

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: geany 1.32-2
ProcVersionSignature: Ubuntu 4.15.0-66.75-generic 4.15.18
Uname: Linux 4.15.0-66-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.20.9-0ubuntu7.7
Architecture: amd64
CurrentDesktop: XFCE
Date: Mon Oct 28 12:48:48 2019
InstallationDate: Installed on 2019-07-08 (111 days ago)
InstallationMedia: Xubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
SourcePackage: geany
UpgradeStatus: No upgrade log present (probably fresh install)