Note the router is a VR2100, not 2800 as the 2100 is not listed in the Model box!
I've had the 2100 for since July and have found that it's started rebooting on a daily basis at around the same time (just after 1pm). The lights go off/on and the logs seem to reset to 2016-01-01 for a few minutes. As far as I can see, the reboot schedule is off and firmware is up to date.
This is extremely frustrating as it drops in the middle of video calls.
Here is the start of the logs, let me know if you need anymore information:
2016-01-01 00:00:28  System: DSL Training
2016-01-01 00:00:41  DHCPD: Send ACK to 192.168.1.100
2016-01-01 00:00:41  System: Enable Parental Controls
2016-01-01 00:00:41  System: Enable IPv4 SPI Firewall
2016-01-01 00:00:41  System: Enable IPv6 SPI Firewall