Here is the board
/system resource print
uptime: 22m33s
version: "3.16"
free-memory: 112952kB
total-memory: 127548kB
cpu: "MIPS 24K V7.4"
cpu-count: 1
cpu-frequency: 680MHz
cpu-load: 8
free-hdd-space: 29752kB
total-hdd-space: 61440kB
write-sect-since-reboot: 163
write-sect-total: 239597
bad-blocks: 2
architecture-name: "mipsbe"
board-name: "RB433"

It acts as dhcp-server in one subnet with about 2-3000 active dhcp leases it reads na dhcp info from radius-server ( free-radius) the mikrotik isn`t the gateway of the network it acts only as dhcp-server nothing more , any ideas ?.

Try to generate support output file on the router immediately after reboot and send it to support@mikrotik.com