I ran into this too until I figured it out.
The first time you run a new pf3.exe file you need to right click on the file > click properties > general tab, look at the bottom of the page and there is a checkbox "unblock" this exe file.
I must have some elevated security setting in Win 11 that blocks new .exe files until you specifically unblock them. I have to do this each time I download a new beta.