RB 2011 100% CPU Usage

Hello everyone, we’ve got RB2011 in our production. ROS version is 7.11.2.
Every 2-3 days, the CPU load rises to 100%. The problem is solved by rebooting, but after a few days the scenario repeats. We did the RouterOS update, the firmware is also updated and corresponds to the RouterOS version. The greatest CPU load in the Profile menu is Unclassified parameter.
Maybe someone has a solution ?
I understand, that RB2011 is pretty old router, but the load is not so much (20 mbit from ISP’s uplink)
RouterBoard.PNG
Profile.PNG

20 Mbit/s is enough to fully load a 2011 when it has to encrypt/decrypt the traffic.
Unless you show the config export, nobody can help you with a solution.

Wireguard is used for VPN, but there is almost no traffic.
Also, as I mentioned, CPU load happens ones in several days and doesn’t disappear until I reboot the router.
Also during CPU 100% load it doesn’t seems to freeze or stuck - the performance is pretty good

is good to post your config but be sure of removing all private info before

Also first check that when the load is 100% there is not a lot of wireguard traffic.