i am using mikrotik 750 sometimes ports got hang and that time only 2 ports are in working and those 2 ports are ethernet 5 and ethernet 1

and sometimes i also see this that if i reboot the mikrotik it halt whole system then i have to remove the power supply and connect the power again to start the mikrotik then it work fine

i am using latest version of RoS 6.30
and Firmware 3.24

routerBoard 750 sn:288e017d94e4/034
if instal 6.30.1 or up to 6.31 (firmware 3.24) gone interface 2 3 4 5 and 100% CPU use
only if return to 5.26 all become work fine!