I'm using Lubuntu 20.04 with LXQt desktop environment. I need to have 2 keyboard layouts (English/Persian) and be able to switch between them. I turned off input methods and am using only the default Lubuntu Keyboard Settings to set Win+Space keys for changing layouts. The problem is that it works for switching from English to Persian but when I want to switch back, actually LSHIFT+SPACE keys can do the job and Win+Space doesn't work at all. I tried it with other layout combinations like English/France or English/German and they all work well both ways. I even tried to read and compare layout files in /usr/share/X11/xkb/symbols directory but found no clue.
ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: lxqt-config 0.14.1-0ubuntu3
ProcVersionSignature: Ubuntu 5.4.0-62.70-generic 5.4.78
Uname: Linux 5.4.0-62-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.14
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: LXQt
Date: Fri Jan 22 22:51:33 2021
InstallationDate: Installed on 2021-01-06 (15 days ago)
InstallationMedia: Lubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
SourcePackage: lxqt-config
UpgradeStatus: No upgrade log present (probably fresh install)
Confirmed and tested with upstream Git master. Seems the issue is specifically with the Win+Space shortcut. Other Win shortcuts are no problem. Also the issue is getting *out* of certain layouts. Set Persian as default and English to second and you can't switch at all. English first, Persian second at least allows one switch to Persian. Just can't get out of it. Other layouts are affected as well, notably Afghani.