Hi fox-orian,
I am sorry you are having problems with the system but let me help you.
I see you have done many steps and all the post is very informative but I would like you to check some more information.
- How far are you from the router?
- Have you tested a different router or maybe a hotspot?
- Is there any way to test different antennas?
- Can you try updating the BIOS of your systems?
Kevin m