If I go onto the AADE.gr web site using Firefox on Windows 10 Pro, I find that uBlock Origin reports that it has blocked 15 links and Privacy Badger reports 7 potential trackers blocked. Chrome on Windows 10 Pro doesn't object to connecting at all, although I haven't installed any third party blockers on it, so it sounds like it is something in macOS that is causing the problem? Perhaps your macOS on your Macbook deals with these possible threats differently? When I first connected, Avast reported it as a safe site but when I went back it said that it didn't have enough information.
Doesn't your Macbook offer an option to override it?