This details the situation whilst logged on as admin. After opening and signing into Teams with licensed O365 creds for the first time, once the application is closed it won't re-open again. Either a blank white window with MS Teams in the title bar opens or the Teams icon displays in the system tray and no window opens at all. Whilst this is happening dozens of teams.exe processes change between 'running' and 'suspended' in task manager. Troubleshooting led me to deleting the settings.json file from %appdata%\Microsoft\Teams, the app would then open correctly but the same scenario would occur after signing in. Further troubleshooting has led to enabling run as administrator on C:\Program Files (x86)\Microsoft\Teams\current\teams.exe. This completely resolves the problem for the admin user but any other user trying to launch Teams on the shared desktop is greeted with a UAC prompt.
I'd rather solve whatever it is i'm doing wrong rather than workaround running Teams as admin for all users. Any suggestions on how i can troubleshoot this further?