MathCAD not opening

Mathcad Prime 6/7/9 not launching after initial splash screen, instructions in

Solved: Mathcad Prime 4.0 doesn't start anymore. - PTC Community

CS277907 - Mathcad Prime does not launch after the initial splash screen if Windows update KB4055002 for Microsoft .NET Framework 4.7.1 installed on the machine (ptc.com)

Mathcad Prime does not launch after the initial sp... - PTC Community

Does not help, everything on there has been tried.

We have the newest W11 enterprise editions with latest updates, software has been tried to run with admin rights as well local/domain admin accounts.

No logs have been recorded in programdata and config files are almost empty before/after deleting .conf

"<?xml version="1.0" encoding="utf-8"?>
<configuration>
<userSettings>
<Spirit.Properties.Settings>
<setting name="UpgradeSettings" serializeAs="String">
<value>False</value>
</setting>
</Spirit.Properties.Settings>
</userSettings>
</configuration>"

Does anyone have any idea what could cause this problem?

Thanks dearly,

Tom