Unfortunately it seems like it was just a glitch while Apple was releasing beta 3. At least it's now back to the same sad situation (for me at least).

We just re-tested this. For some unknown reason it seems to work now. Existing shortcuts still open wrong, but a newly added one works fine. Even opening an old shortcut and re-adding it to homesceen seems to work. Can anyone verify / are you experiencing the same?

Same issue here. This is highly problematic. Hopefully it will be resolved in following betas.