The “30 second restart” is reset to factory default ?
If you tried that already sorry to say you may have ‘bricked’ it. :-(
Also try an IP survey, could it have somehow ended up at a different IP address?

I tried the 30 second restart which is supposed to be the hard reset for them and it didn’t work, tried to get it into management mode and that didn’t work either (hold reset for 5sec and unplug and plug back in).

I’ve googled a few things on it and those are the most frequent “fixes” I’ve seen.

The ‘30 second” restart included pushing the tiny ‘reset’ button?
If you did all that, it’s hard to think of what else you can try unless you are good at de-soldering the EPROM and have a factory fresh one to put in its place.
Could be time for the recycling bin.

Disconnect all cables from the router except for the power cable. Hold the RESET button for 30 seconds. With the RESET button still held down, unplug the router from its power source and keep holding down the RESET button for another 30 seconds. Plug the router back into its power source and continue to hold down the RESET button for another 30 seconds (90 seconds in total). Flush your DNS cache on your computer (typing ”/ipconfig release” then ”/ipconfig renew” in Windows). Connect an ethernet cable from computer to a LAN port on the router and try contacting the router at 192.168.1.1. If this doesn’t work, your router has been physically damaged and will need repair.