localstarlight

I'm at a total loss here. Have now tried installing Houdini 20.5.410 on three different machines on our render farm, and it's the same thing on all of them (but working fine on my own local machine).
Have tried completely uninstalling all versions of Houdini and the launcher and starting all over again, still not working. Just no idea where to go from here since it's not throwing any errors.
Any help much appreciated here, as on a deadline and need to get this working asap.

Windows 11.

I have been runnning Houdini 19.5.716 but have just upgraded to 20.5.410 and it just won't launch. The splash screen appears for a while, and then just disappears. No errors in the console or elsewhere, no crash logs, it just doesn't load. With the lack of errors or logs, how can I even diagnose the issue here?
Has anyone experienced anything similar? Is there any way to figure out what's happening here?