once the core seems to be online, the core immediately flashes red light, and tried to restart again, the process takes turn, so core constantly connects to the local server, but then immediately drops it. maybe after several minutes, the core prints out another text saying:
Hi @helxsz - what firmware do you have on your Core? You can try flashing tinker to see if that helps:
particle flash --usb tinker
The core should then connect to the local cloud and breathe cyan. Let me know if that resolves the problem, and we can then look at your application to see if there is any issue there.