You know how the interconnected network works? What nodes are? And routing? Backbones? The "Last Mile"? Somewhere inbetween might be the problem, and it is not necessarily on Square Enix' end.

I could explain you all that and you might understand why the connects (this is a 90s term of how well/how fast a connection is established) can vary.
I do understand from your "Installed this game like 4 or 5 times" that you retried it several times. During Shadowbringers my installations interrupted and have been cancelled, sometimes I had below 1 MByte/s downstream. Suddenly I got lucky and had a fine connection of 6 MByte/s (50 MBit/s).



So, you might retry or try again off-hours. The servers can be iffy, but if your provider is having massive load, Square Enix can't fix much.


 Sincerely,