Routers of different models, including RB2011, RB1100, RB912, RB951. Version RouterOS 6.42.1. Works l2tp, sstp, radius, a dozen VLANs, NAT, mangle, firewall (fatty router firewall two hundred rules in total). And queues simple queues, OSPF, GRE tunnels, IPSec, certificates, capsman, WiFi and hotspots.
25 APR normal flight, unplanned reboots were not.
Maybe a config problem?