Hi, really sorry for the inconvenience! When running the updater myself it has no problem connecting:
I'm not sure what's going on for you as I've never had anyone report this issue before, so it may be something else on your computer blocking it. I do plan to release a standalone version of pro in the future, so eventually this issue should be gone!
Do you have a twitter or discord where I could privately send you a copy of pro? Saves you needing to go through the installer :)