Are you using a VPN? no
Are you using a wired or wireless connection? wired
What Platform are you using? (Steam/Windows/Mac/PS4 etc.) all effected persons are using Windows, no Steam.
Does the issue occur with one character or multiple characters? considering its numerous people, its multiple characters.
At what point do you get disconnected and/or are unable to connect? usually after 10pm EST but it can be earlier as well.
How often does the issue occur? Every day.

Internet Service Provider: various.
Region/State: various. from California, to the midwest, to New York, to Canada.
All steps taken to resolve the issue: restarting computer, rebooting internet modem and routers, having ISP technicians out to the homes to check connection (No issues found). Tried using a VPN.

The hardware these people use varies as well, from Intel i5-12th gen and 3060s, to Ryzen 7000 series with 4090s, to gaming laptops with 4000 series Nvidia graphics. It isn't limited to older CPUs or GPUs, or laptops or desktops. All have at least 16GB of RAM. All have SSDs. Everything else runs perfectly. It's JUST FFXIV failing. They can crash in this and then load up another online game and be fine, or another AAA title and be great.