@nil_sak_13 

Hello, thanks for reporting the issue but please provide some details about the auto-reboot issue then we will try to investigate and offer a solution ASAP.
1. When the router reboots, are all the LEDs turn off then on automatically and the internet on it will temporarily down then recover? How long does this process take?
2. May I have your network layout, how is the C60 connected to your network? Are there any other range extenders or switch in the network? If yes, try to remove it first and confirm again. 
3. Who is your ISP and what kind of modem are you using? Is it a Dynamic IP setup on the C60 WAN or PPPoE?
4. How many devices are connected to C60, wired, and wirelessly? What are they? Is there any new device connected to the C60 network recently when the C60 begins to reboot? Or did you upgrade any system in the network before this issue happen? If there are some iOS14 devices connected to the C9 network, try to disable the Private MAC address on the iOS devices, then monitor again.
5. Is there any other setting or feature in your network that may cause this restart issue, or is there any special operation/activity in your network that causes the C60 to restart, such as high loading or real-time calls?
6. Is it the original power adapter on the C60? Is the power stable in your house? How about other electrical devices in your house, are they stable?
7. Does this issue happen when you purchased it or happens recently? Try to reset the router to factory defaults and reconfigure it from scratch, then confirm again.