I used the latest FlyByWire A320 installer. Starting up, it loaded to 100% and then sat there. I literally let it go for several hours without completely loading.
I then used the uninstall feature and it did not completely remove the installation in the Official OneStore folder. I manually deleted the folder.
Then I downloaded via the Direct Download (https://cdn.flybywiresim.com/addons/a32nx/stable/full.zip). I installed in the Community folder. Upon loading the FBW A320 Neo (Leap), it did take a little while to load, but finally worked for me.
This happened on two different computers, so I am confident of the solution for me.
I post this in case this might help someone else.