possible bug? #innodb-encryption-threads

hi team

I'm having a peculiar situation, a problem here with my config, which config is pretty galera-vanilla.
Namely, if I set these:

plugin-load-add = file_key_management.so

file-key-management

file-key-management-filename = /var/lib/mysql/.keys.txt

innodb_file_per_table = 1

innodb-encrypt-log

innodb-encryption-threads = 4     <= # this ! one here

I get constant load on four cores, it would fluctuate just under %400 CPU (24*7). I'd assume that innodb-encryption-threads value causes it, and whatever the value might be it will be reflected in CPU usage.
I wonder if you too see it.
I my case I think it does something more to one system, it crashes the bloody thing to the extent where cold reboot is needed.

MariaDB-client-10.1.19-1.el7.centos.x86_64

MariaDB-shared-10.1.19-1.el7.centos.x86_64

MariaDB-common-10.1.19-1.el7.centos.x86_64

MariaDB-server-10.1.19-1.el7.centos.x86_64

best,
L