Start11 is version 2.07

Windows 11 is version 23H2 ( in case this matters )

You are correct, I'm using "Windows 10 style".  I attempted what you suggested, but get the same error message when trying to launch via the pin in the group:

Launching it from that left menu under Suggested Apps, it does correctly open the app:

No, if I pin it from the menu under Suggested, if I click on the pin in the right tile area under the group "Main" I get the same error that it can't find the app.

Thanks,

Yes, this version of Teams is the Windows App.  I wasn't able to create the shortcut "C:\Windows\explorer.exe Shell:AppsFolder" but I was able to Start + Run then shell:AppsFolder
That opened up the Applications folder, where I created a shortcut of "Microsoft Teams (work or school)" and that shortcut became created on the desktop, which I named "Microsoft Teams (work or school) NEW".  I copied it into C:\ProgramData\Microsoft\Windows\Start Menu\Programs, terminated explorer.exe and started explorer.exe again and couldn't find it in the Start11 start menu so I copied that same shortcut into C:\Users\myuserprofile\AppData\Roaming\Microsoft\Windows\Start Menu, terminated explorer.exe and started explorer.exe again and this time the new shortcut appeared under the Suggested pane and I right clicked that new shortcut, which does work via the shortcut itself and the Start11 Suggested area as a pin to a group and then when I try to launch that program via the pin I get the same error.

What I am observing in the screenshot after I create the pin, is if I delete the pin with my custom icon and name and then re-create the pin, it has the same name and custom icon.  I wonder if there is some kind of db that's keeping this change and if my customization of the icon is what caused this?  I am going to try uninstalling Start11, delete all program folders/files/registry and re-install and see if by default I can't get that shortcut and pin to work.

Ok so all of that effort did it, uninstalled, rebooted, deleted all left over folders from all places (I work in IT so I know where to find all this) I then even went a step further and completely uninstalled Teams, this is where I got the re-install from: https://www.microsoft.com/en-us/microsoft-teams/download-app and the file the program installs from is MSTeams-x64.msix, made sure that the normal Windows 11 start menu could launch that after install and made pin that to the normal Windows 11 start menu, then re-installed Start11, activated trial again and left all defaults and after install the Teams shortcut was already under Pinned and launching it from there worked.  Now to see if I can re-name it and customize the icon, reboot and see if the pin app still launches.

It was unusual that your second teams app had no icon in the explorer all apps folder too.

Something seemed broken with that.